Statistical Diplomacy: A Bayesian Inference Tool for the P5+1+Iran Negotiations

This is an abridged version of the full paper Statistical Diplomacy: Nuclear Negotiating Strategy Applied to Hassan Rouhani (the result of the process I began with “Iran: So Far Away“).  I have prepared it as a possible negotiation aid.  It is still in working paper form.  As such, comments will be thoroughly appreciated.  Please email for a copy of the spreadsheet, including your name, your affiliation, and your email address.

Life can be modeled as a tree of future events with branches that will be realized with different probabilities.  Each branch can be thought of as forked paths in the forest.  Each branch in the past or the future relates to other branches.

Bayesian inference offers a method to relate the conditional probability of a certain branch to the probabilities of other branches.  This can be a useful tool in improving the odds of achieving a desired result.  I have applied such a tool to the Iranian nuclear negotiating portfolio, looking at the situation from the perspective of the P5+1 negotiation team (a tree created from Iran’s perspective would have different nodes and primary goals).  It is simple in concept, yet surprising in results.  This tool, which I have modeled in Excel spreadsheet form, can help to realize the implications of various decisions on the ultimate outcome: an Iran with or without “the Bomb.”

Bayes in a Bombshell

Let us suppose there is a nation-state that might be developing weapons-capable technology (meaning technology with both weapons and civil applications).  None of these decisions or results are known (ex-ante) at the present time, but both can be estimated via probabilistic techniques (the initial percentage estimates would come from said nation-state’s past actions, and public statements and written works made by national leaders).

Figure 1 – Example: Weapons-Capable Technology and Weapons Outcomes

The branching node at the left represents the total probability of nation-state’s development of weapons capable technology.  The nodes in the middle are conditional on the branch they lie on.  Thus, the upper-branch probabilities (weapons or no weapons) are conditional on leftmost node (weapons-capable technology development or not).  The outcome nodes on the right can be calculated by multiplying the probabilities of the paths through the branches to the left.  Thus, the probability of developing the technology and creating a weapon is 50% * 75% or 37.5%.  I refer to reader to the excellent Wikipedia article for a more detailed explanation (with a more lighthearted example).

An interesting result is that by estimating the probabilities at the nodes, one can estimate the probability that the nation-state will obtain weapons by summing up the end nodes (the rightmost nodes) that result in weapon creation, via production or external purchase (37.5% + 5% = 42.5%).

The Bayesian trick is that the tree’s branching nodes can be reversed as shown below, putting the “weapons” question first:

Figure 2 – Example: Reversing the Nodes to Get Useful Results

Each tree is consistent with the other.

From the analysis we can infer a useful result: that the probability of the nation-state using the weapons-capable technology to develop weapons is 88.2% (calculated from the probability of developing the technology AND weapons divided by the total probability of a weapon as calculated above, or 37.5% / 42.5%).

The formula and notation for this would be:

P(Tech|Weapons) = P(Tech & Weapons)/P(Weapons)


P(Weapons) is read “the probability of weapons”;

P(Tech|Weapons) is read “the probability of the tech conditional on the probability of weapons”;


P(Tech & Weapons) is read “the probability of the tech AND the weapons.”

Another important conclusion is that by calculating a variety of component tree probabilities, we can use algebra or a spreadsheet to derive additional consistent probabilities.

Finally, even if our probability estimates are not perfect, using reasonable best guesses can improve the likelihood of obtaining the desired results.  In this case, it is clear that we can lower the probability of a weapons outcome by convincing the nation-state to take the “no” branch for the weapons-capable technology.  The technique lets the negotiating team quantify their estimates of improvement by achieving certain branches; and thus prioritize their negotiating strategy.

How to Use the Technique for Iranian Nuclear Negotiations 

The situation in the Iranian negotiations can be characterized in a more detailed tree.  I have extended the tree to the following decision nodes. The current version of the tree has been modeled for the P5+1’s negotiating team.  Their apparent objective is to minimize the probability that Iran obtains nuclear weapons. The tree nodes are

Table 1 – Model Tree Nodes

Branch probabilities were estimated from President Hassan Rouhani’s published works, former actions, assessments written by other authors in the diplomatic and arms control fields, and other assessments on Iranian nuclear goals.  Probabilities are assumed to be within about 5 to 10% of the true value.  The assumed probabilities are detailed in the spreadsheet, which is available upon request as detailed at the bottom of this article.  I also have written a more detailed 20-page academic journal style paper (that I hope to have published, hint to journal editors) and which I can provide on request to interested parties.

Figure 3 – Nuclear Negotiation Tree Model

The tree is show above in miniature in Figure 3.  Please click on this link for the high-resolution pdf.  Each probability estimate is shown for the yes (up) and no (down) nodes.  Note that italics are used throughout to denote node decisions as shown in the second row.

Users can enter and use their own probability estimates.  Certainly, others can provide better estimates than I.

Analysis Results as Applied to Negotiation and Discussion

As the objective is to minimize the probability of Iran’s acquiring nuclear weapons, the most useful results are how various branch decisions that can be affected by negotiation change that probability. The absolute accuracy is only as good as the (somewhat subjective) input estimates, but even if the assessments are +/- 10% or more, the relative changes in probability are extremely useful.  I present results to 0.1% in the calculation for clarity to the reader following the calculations.

Table 2 – Analysis: Key Results

Key Negotiating Take-Away 1: The Effect of the Medical Isotope Program

For the past several years, Iran has insisted that 20% enriched uranium is necessary to fuel the Teheran Research Reactor, which in turn produces medical isotopes for internal diagnostic and nuclear medicine purposes.  What would the estimated effect be of such a medical isotope program (abbreviated “Medical Isotopes” or “Iso” on the spreadsheet) on the probability of Iran obtaining nuclear weapons (abbreviated as “Bomb“)?

First, for comparison, the base case Bomb probability estimate must be calculated. Multiplying all the conditional probability estimates in the tree will yield the right-hand node paths probability estimates.  Then summing only those where Bomb results reveals this probability.  Thus, the base case Bomb for comparison purposes, sums to 52.2%; i.e. there is a 52.2% chance (+/- the analysis error) that Iran will obtain a nuclear weapon.

Now, if only paths are considered where Iran has a Medical Isotopes program the Bomb probability is increased to 61.9%, i.e. almost 10%.  However, if the Medical Isotopes program is eliminated, the Bomb probability falls by about half, to 29.7%.

Therefore, successfully negotiating with Iran to eliminate the 20% enriched uranium Medical Isotopes path lowers the risk of the Bomb outcome significantly.  This should be one of the P5+1’s primary negotiating objectives.

Applying Bayes’ Theorem to reverse the calculation, as shown in the second tree example, reveals the probability that IF Iran creates the Bomb, it has a Medical Isotopes program.  This is a very high 82.9%. Thus if Iran creates a Bomb, a Medical Isotopes program is highly associated, possibly as cover.

Overall, analyzing this aspect of the tree yields two important findings.  First, if Iran has a medical isotope program, its probability of obtaining a nuclear weapon increases by 9.7%, to 61.9%.  Second, if Iran does create a nuclear weapon, there is an 82.9% chance that it has a medical isotope program, and possibly used as cover to enrich uranium to a higher level.  This strongly indicates to P5+1 negotiators that they should make preventing Iran from keeping a full medical isotope program a high priority, as the isotope program’s existence greatly increases the likelihood of a nuclear-armed Iran.

Key Take-Away 2: The Effect of Fuel Cycle (3.5% enriched Uranium)

It appears to the Wonktern that the Iran commercial power fuel cycle (the “Fuel Cycle”) is already a foregone conclusion in any negotiated settlement.  Nevertheless, what is the effect of eliminating the Fuel Cycle as compared to maintaining it?

Again, from the base case estimate of a 52.2% probability of Iran producing a Bomb if we only consider the paths of maintaining the Fuel Cycle, the probability of the Bomb is increased to 60.2%.  However, if the Fuel Cycle is eliminated, the probability of Iran’s obtaining the Bomb is estimated by the model to be reduced to 24.6%.  In the model’s estimation, it is only marginally better to eliminate the Fuel Cycle than to simply eliminate Medical Isotopes.  This marginal benefit and massively increased negotiating difficulty indicates that the P5+1 should focus on the more realistic goal of eliminating Iran’s medical isotope program.

Key Take-Away 3: Compounding the Fuel Cycle and the Medical Isotope Program

If we consider the joint probability of the Fuel Cycle together with the Medical Isotope program (read: both or none), the effects on curtailing the acquisition of the Bomb are enhanced.  Conditional on both Fuel Cycle AND Medical Isotope programs the probability of the Bomb is 68.3%.  When both are eliminated, the Bomb probability falls to 23.2%.   Ignoring how one could have a medical isotope program without a fuel enrichment program, we see that eliminating the Fuel Cycle program in addition to the Medical Isotope program only decreases the probability by about 6%, compared to eliminating the Isotope program all together.  Both P5+1 and Iranian nuclear negotiators must decide at what point attempting to eliminate the Fuel Cycle, a point that Iran has stood hard on since Rouhani’s days as a negotiator, is not worth the risk of jeopardizing other negotiation gains.

Key Take-Away 4: Genuine Negotiations vs. Iran Subterfuge Strategy

For the P5+1 negotiators, there is no way to determine if Iran (by political implication both Rouhani and Khamenei) is genuine in its willingness to agree to a settlement (“Genuine“) without nuclear weapons.  For the P5+1 negotiators, this is just another unknown decision node with probabilities.  In the model, this has been subjectively assigned a 50/50 probability and is not conditional on other decisions (i.e. it is the left-most node).

For Iran, it knows whether it is being genuine or not; and by changing the decision to be genuine, it can greatly influence the probability of its acquiring nuclear weapons (the Bomb). If Iran is Genuine, the probability of its acquiring the Bomb is reduced to 33.1%.  If it is not Genuine, the probability increases to 71.3%.  Clearly, the P5+1 should look for telltale signs that Iran is following the non-Genuine path, and modify its strategy accordingly.


Overall, the total probability over all tree paths lead to Iran obtaining a nuclear weapon just over half the time.  Thus, western policymakers must use clues that Rouhani gives during negotiation to determine which path of the decision tree Rouhani is following.  Negotiators can use Bayesian inference with the aforementioned tree method to derive Bayesian conditional probabilities.  Once they determine the probabilities of each of Iran’s actions on separate branches of the tree, negotiators can tailor strategies to each situation that arises to increase the chances of the desired result.

Concerning overall strategy, it appears that the West should pursue a mix of policies that encourage Iran to not progress past a commercial power fuel cycle.  One of the West’s primary negotiating goals should be to secure the negotiated elimination of Iran’s medical isotope program.

To achieve this strategy goal, the West can openly offer relaxation of sanctions, as well as increased trade with Iran.  However, using the probability tree, P5+1 negotiators can statistically estimate whether a strategy of initially offering a full fuel cycle, a “stick and carrot” approach, or implicit, wink-and-nod style signals would encourage the optimal result — no Iranian nuclear weapons.  Western negotiators will determine what appears reasonable to exchange in return for an agreed Iranian fuel cycle. The most optimal outcome would be obtaining a mostly, if not totally, transparent peaceful civilian nuclear program with limited or no breakout capability.  Over time, increased economic contact between Iran and the West should chip away at the tensions between the nations and cultures, decreasing the chance of weaponization attempts.  On the subject of Iranian medical isotope program, the West should offer to create a multinational isotope production facility that could replace the TRR (in the manner described in greater detail in my academic larger paper).  Aside from the medical isotope program’s role in exposing Iran’s path on the decision tree, it could also serve to remedy similar problems with other nations that are nuclear weapons proliferation risks, but would still desire to have access to nuclear medicine.

The event tree will be a valuable tool to Western negotiators in dealing with President Rouhani.  If used correctly, negotiators can create strategies that have an extremely high chance of success, and resolve the diplomatic mess that is the current state of Iranian and Western relations.


  1. Cthippo (History)

    I’m not a mathematician so none of what I’m about to say may be valid, but…

    How does it change things if you eliminate the unreasonable paths (ie, Iran does not develop nuclear technology but still gets the bomb)?

    I also question the assumption that the desired outcome is Iran as a functioning non-nuclear weapons state. I’m not clear that this outcome would even be acceptable, much less ideal, to many in the US congress who have the power to block removal of sanctions.

    • harry (History)


      1) How does it change things if you eliminate the unreasonable paths (ie, Iran does not develop nuclear technology but still gets the bomb)?

      My spreadsheet is a tool to explore exactly these kinds of questions. If you write me offline, I will send you a copy of the spreadsheet to put in your own estimates of what is reasonable and what is not, and do the calculations yourself. However, to answer your question, I have assumed that “Nuclear Breakout Capability” is what you mean by “Nuclear Technology”, as Iran already has nuclear technology. In my estimates, I still assumed some residual capacity to acquire weapons by other means (i.e. from North Korea), but for your question, we can say that the probability of developing a bomb goes to zero for each child node of the NO Breakout Capability nodes, and recalculate from there. Then some quick answers are:

      P(Bomb) = 43%, i.e. 9% lower than my base case P(Bomb) estimate (52.2%)

      P(Bomb|Medical Isotopes)=53.1%, i.e. 9% lower than my base case estimate (61.9%)

      P(Bomb|NO Medical Isotopes)=19.7%, i.e. 10% lower than my base case estimate (29.7%)

      Using your constraints, cutting out the medical isotopes program still substantially lowers the risk of a Bomb result.

      2) I also question the assumption that the desired outcome is Iran as a functioning non-nuclear weapons state. I’m not clear that this outcome would even be acceptable, much less ideal, to many in the US congress who have the power to block removal of sanctions.

      I have no idea what Obama’s actual goal is. I am just a young student, not a politician. I suspect that whatever Obama negotiates he has a good chance of getting through the Senate, which ratifies treaties. For the House, he may have to get consensus from a broad range of people, but I also suspect that he can by executive order do almost anything that he would like.

  2. Apollo (History)

    I recommend that you look into Bayesian belief networks and influence diagrams for this type of decision analysis. You’ll find that these more concise representations facilitate casting the problem more realistically and the built-in inference engines facilitates answering a broader set of questions than with the explosion of branches in a decision tree. (I’m a fan of BayesiaLab by Bayesia for this type of analysis; and you can download a free demo version at .)

    • harry (History)


      Thank you for your suggestion. I will look into Bayesian belief
      networks and these software tools, although nothing beats the clarity
      of a simple spreadsheet for explaining a new idea. I appreciate the
      leads, and perhaps I will use them in future papers.

  3. Rene (History)

    Thanks so much for this insightful analysis! I have a basic question: where do the probabilities for moving from one node to another come from? I ask this because contrary to your 75% estimate I think it is unlikely for Iran to sprint toward a bomb, even if they have the technology, because no one in the UNSC is going to stick up for them (unlike Israel, India, and Pakistan) and because they’re totally dependent on outside trade (unlike North Korea). In other words, my sense is that the probability of making the sprint is different for each country, depending on their foreign relations and patterns of trade.

    • harry (History)

      Hi Rene,

      I will attempt to answer your questions:

      “Where do the probabilities for moving from one node to another come from?”

      The conditional probabilities come from my subjective estimates. I
      believe they are reasonable, but you may have other information.
      Also note that the Iranian team itself has even better estimates of
      these probabilities than the P5+1 — they know their own plan very

      “I ask this because contrary to your 75% estimate I think it is
      unlikely for Iran to sprint toward a bomb, even if they have the

      That is the point of my spreadsheet tool. You, or the diplomatic
      negotiation teams, may use a free copy of my spreadsheet and plug in
      your own conditional probability estimates to arrive at your own
      conclusions, or to test the effect of changing the estimates on
      the relative outcomes. The email address to request a copy of the
      spreadsheet is contained in the original post in the first paragraph.
      I am providing this new spreadsheet tool for others to use.

  4. Jonah Speaks (History)

    I am a great fan of Bayes’ Theorem. It can be used to estimate the age of the universe and to test new drugs more efficiently. Its usefulness, however, depends on how well it is applied, the additional assumptions one adds to the analysis, and whether those assumptions make sense.

    I have two concerns. One is that each option is a yes or no, but I think it makes a difference how one gets to yes or no. If it is a voluntary decision by Iran, it may be more predictive. If it is a forced decision, or a negotiated decision, its effects on the probabilities may be different than if the decision is strictly voluntary.

    The other concern is that negotiations may be about more than medical isotopes (20%), yes or no, or fuel enrichment (3.5%), yes or no. There can be a “yes, but with clear limits.” These could be limits on production, limits on stockpiles, limits on centrifuges, or other limits.

    You might want to think further about how these in-between possibilities might be fit into your model. For example, a forced no might be 2/3 yes and 1/3 no. A negotiated no might be 2/3 no and 1/3 yes. There might also be alterations in probabilities, depending on how constraining the limits are on “yes, but …”

    • harry (History)

      Dear Dr. Lundgren,

      I will look to incorporate your suggestions in a revised version of the model in the future.

      Thank you.

  5. hass (History)

    This was a loto of work, kudos, but it rests on the faulty assumption that the curent standoff between the US and Iran actually is motivated by the nuclear issue, when in fact the nuclear issue is merely a pretext and superficial justification created and deliberately maintained at a certain level of hype, because it serves as a convenient political cover and pretext to pursue an entirely differnt agenda of imposing regime change on Iran. You can’t just assume that one side’s motiviations are geniune whilst the other’s is suspect. What if the US does NOT WANT to resolve this issue?

    • harry (History)

      Dear Hass,

      My spreadsheet analysis is a tool that can be modified. If you or the Iranian diplomatic team want to include 2 new tree decision nodes: “U.S. Secret Motive Regime Change” and “CIA Does Regime Change”, it is free for either of you to modify. I estimate the probability of the Obama Administration secretly planning regime change or actually doing anything about it to be nearly zero (look at Syria), but your estimate may be different.

      Please email me for the sheet at the address in the article. I will explain in detail how the spreadsheet works so you can add or replace a decision/outcome node.

    • Hass (History)

      Yes but the point is that your decision tree as it is now, simply assumed good faith on one party, and only investigates the options of bad faith on the side of another party. That’s simply not a way to analyze any such dispute, it doesn’t have to be about Iranians per se. Unfortunately there is a tendency to assume that “we” are good and honest and forthright, whilst “they” are not (whomever we or they may be.)

      The idea that the nuclear issue is being used as a pretext is not some wild and crazy conspiracy theory; we already saw that “WMDs in Iraq” being similiary manipulated. Even IAEA head Mohammad ElBaradei reached that conclusion: “They weren’t interested in compromise but regime change by any means necessary.”

      Obama may not be “secretly planning regime change” — this may be a policy that the Obama administration inherited, and it is questionable to what extent he can change it considering for example that the sanctions can’t be lifted and so Obama is entering negotiations with one hand tied.

    • Jonah Speaks (History)

      Haas, As I read Harry’s model, it is bomb-oriented, not blame oriented.

      His model is addressed to the issue, how can there be assurance that Iran will not build a nuclear bomb? One can read this from the world’s perspective, “How can the world be assured that Iran will not build a bomb?” One can also read this from the Iran’s perspective, “How can Iran assure the world that Iran will not build a bomb?”

      The model does not tell us (one way or the other) that Iran is either trustworthy or untrustworthy. Nor does it tell us whether the world is trustworthy or untrustworthy. The question of whether Iran undertakes a genuine negotiation is a true uncertainty that belongs in the model – because it is not apparent even to experts whether Iran plans a genuine negotiation and because it helps to predict whether Iran will build a bomb. The question of whether the world undertakes a genuine negotiation does not obviously belong in the model – it is not necessarily predictive of whether Iran builds a bomb.

      The model is one way, not interactive. It is not a “game theory” or bargaining type model. It tries to illuminate the issue, “how much is it worth to seek various bargaining outcomes,” but it does not say how much each side should give up or demand to achieve those outcomes. It neither advises nor predicts how or whether each side negotiates, nor the “price” each side should set or accept.

      For what it is worth, I believe the Obama administration is engaged in genuine negotiations. Congress is unlikely to approve a future war, even if ever-stricter sanctions on Iran appears to be its current mood. In the event Iran made a credible effort to assure the world it will not build a bomb, Congress is unlikely to pass additional sanctions and the world (including Europe, Russia, and China) is unlikely to cooperate in enforcing existing U.S. sanctions.

    • hass (History)

      But Jonha, it is INHERENTLY blame oriented when it is bomb-oriented rather than, lets call it, politics-oriented.
      The dispute between the US and Iran is not really about nuclear power or nuclear weapons etc. — those are simply manifestationf of a POLITICAL conflict underneath. We can’t be naive about this and arbitrarily impose a framework around our analysis which simply takes it for granted that those sneaky Iranians could be up to no good with nukes nevermind the context.

      Any such analysis can’t just be based on questioning only one sides’ motivations. In so doing, it ignores the fact that in this dispute the Iranians may have their own Bayesian analyss of suspect motives that they (quite justly) attribute to us. When you consider this fact, it makes the analysis far more complicated because of the permutations of suspect motivations increase substantially when both sides could be lying.

    • Jonah Speaks (History)

      To reiterate, the model says nothing about whether Iran is innocent or guilty. The model is neutral, even if it does not reflect the fanciful “reality” where Iran is an innocent victim of unjust U.S. machinations.

      In reality, it is the world, including Russia, China, and Europe (Britain, France, and Germany), which are quite suspicious of Iran’s purportedly “peaceful” nuclear program. This world concern is evident in 4 U.N. Security Council resolutions which Iran refuses to comply with, and in IAEA resolutions that Iran likewise does not comply with. This non-U.S. world is not inclined to follow the U.S. lead when the U.S. spouts nonsense. Far from being an innocent victim, it is Iran’s own behavior which has prompted this world opposition.

      Nevertheless, if Iran is innocent, and is willing to demonstrate its innocence, nothing prevents Iran from negotiating itself out of the nuclear box which Iran has fallen into. More likely (in my view) Iran is guilty, needs to repent, and needs to walk a credible path to redemption. Either way, Iran is fortunate that the world’s powers are willing to negotiate.

  6. kme (History)

    It seems that by far the most important unknown for “this side” of the issue is Iranian intentions – the question of whether or not Iran currently intends to build a bomb.

    To this end, a Bayesian analysis of Iranian decision trees in the past, where many decisions are now known, might well be illuminating. For example, there are plausible reasons that Iran might build a hidden centrifuge facility under both answers to the intention question – assigning those probability estimates allows you to give a probability estimate of “Iran intends to build bomb” conditional on “Iran builds a hidden centrifuge facility”, which we now know the answer to.

    Of course, the real problem is a lack of hard data from which to generate conditional probability estimates. As long as they remain mostly subjective, the end results are likely to mirror the biases of the person doing the analysis.

  7. fyi (History)

    I think Jonah Speaks phraseology is religious and devoid of analytical content.

    The fact remains that the nuclear-weapons states are loath to see other nuclear-weapons states emerged.

    In case of Iran, learn to live with a nuclear-weapon-ready Iran.

    • Jonah Speaks (History)

      fyi, I see only one sentence in my posts above which contains religious-sounding terminology. “Iran is guilty, needs to repent, and needs to walk a credible path to redemption.” Here is a translation:

      “Iran is guilty” – At a minimum Iran is guilty of not complying with UNSC resolutions, and of not properly answering IAEA questions or permitting IAEA inspections. The substance of Iran’s misconduct strongly suggests it is seeking either a) an actual bomb, or b) a virtual bomb. Possible reasons c) “bluffing” or d) “sovereign pride” seem inadequate to explain Iran’s conduct. A “virtual bomb” (Iran’s most likely goal) means having all the elements needed to assemble a bomb within a short time before outsiders can intervene to prevent it.

      “repent” means “change course of conduct.” In this context, stop aiming to build a bomb or appearing to have this aim. “walk a credible path” means that actions must convince outsiders that Iran has truly changed course, and is not just pretending to repent. “redemption” means the lifting of all or most sanctions.

      More substantively, no, I do not believe we should just “learn to live with a nuclear-weapon-ready Iran.” To allow anyone who wants a “virtual bomb” to have a virtual bomb would simply make a mockery of the NPT.

  8. Jonah Speaks (History)

    Harry, Now back to your model. After reviewing the above exchanges and thinking more about this, I can suggest some other possible modifications.

    One modification is to explicitly model Iran’s possible goals. These might range from “no bomb” to “virtual bomb” to “actual bomb.” For each of these possible goals, there are various chances of Iran moving through the various steps. You have ordered the steps, so this would be 3×6=18 conditional probabilities to work out. This reduces the modeling work from the approximately 2^7=128 conditional probabilities, of which approximately 2^6=64 are independent conditional probabilities in your current model.

    In addition to the 18 conditional probabilities in a revised model, you (or others) would need to estimate the prior odds that Iran seeks each of the 3 possible goals. This is not specifically what were Iran’s goals in the past, but what are Iran’s current goals (say for the next 5 years)? For example, the odds from the non-Iranian perspective for what Iran seeks might be 1/3 for no bomb, 1/2 for virtual bomb, and 1/6 for actual bomb.

    In a negotiation, the non-Iranian goals also matter. For example, Iran might suppose there is 1/3 chance the world will allow only “no bomb”, 1/2 chance that the world will allow “virtual bomb”, and 1/6 chance the world will allow an “actual bomb”.

    If Iran’s goals and the world’s goals are well aligned or allow easy room for compromise, negotiation will most likely be successful. If these goals are somewhat misaligned, negotiating success will be trickier, but might be possible through compromise. If goals are very much misaligned (i.e., “no bomb” allowed vs. seeks “actual bomb”), a successful agreement will prove difficult, no matter how much “good faith” is put into the negotiations.

    In light of certain sensitivities, it might be good to change the label for “genuine negotiations” to something else (e.g., “businesslike negotiations”). Step 1 is really part of a negotiating model, whereas the other 5 steps are part of a bomb-making model (or viewed in reverse, a confidence-in-peaceful-use model). Perhaps step 1 for Iran could be taken out of the bomb-making model and placed into a formal negotiating model, along with a counterpart step 1 for the world’s approach to negotiations. Food for thought and for additional modeling.