In August 2012, President Barack Obama warned that if the Syrian government under Bashar al-Assad used or moved chemical weapons, it would mark a “game-changer”—the crossing of a red line that could shift U.S. policy toward military involvement. Chemical weapons were singled out because of their legal prohibition, moral stigma, and proliferation risks.

In August 2013, Syrian forces carried out a large chemical attack in Ghouta, killing hundreds of civilians. The red line appeared to have been crossed. Yet instead of launching military strikes, Washington pursued a diplomatic agreement with Moscow under which Syria declared and dismantled its chemical stockpiles. Critics argued that the decision not to use force weakened American credibility and diluted deterrence. Supporters countered that the agreement achieved the core objective without another Middle Eastern war.

The episode became a case study in deterrence theory: what happens when a publicly articulated threat is not enforced militarily? Does restraint preserve flexibility—or shrink future bargaining space?

The current standoff between the United States and Iran presents a similar credibility dilemma. President Donald Trumphas threatened sweeping military action if Iran refuses a new agreement restricting its nuclear program—and potentially its missile arsenal. Tehran, for its part, threatens regional escalation, missile barrages, and economic disruption, including risks to Gulf energy infrastructure and the Strait of Hormuz. Yet not all threats on either side are equally credible. That gap—between rhetoric and believable resolve—is where bargaining space either expands or collapses, and where attempts to test resolve risk miscalculation.

Deterrence theory begins with a simple proposition: threats must be credible to work. Credibility rests on three pillars—capability, interest, and reputation for resolve. In the present case, both sides clearly possess capability. The United States has deployed carrier strike groups, reinforced air defenses, and signaled readiness for sustained operations. Iran has demonstrated missile capacity and maintains regional proxy networks capable of retaliation. On material capability alone, each can impose substantial costs.

But credibility is not synonymous with capability. It is the perceived likelihood of follow-through.

Here lies the paradox. The United States has increased deployments and clarified its military readiness, narrowing uncertainty about what it can do. Yet uncertainty about what it is willing to do persists. Is Washington prepared for a prolonged campaign with potential economic shockwaves and global recession? Or is the buildup primarily coercive leverage designed to extract concessions while avoiding full-scale war? The Syrian precedent lingers in Tehran’s assessment: threats may be real, but enforcement is conditional.

Reputation constrains Washington. Repeated threats over the years have not always produced decisive escalation. At times, strikes have been authorized; at other moments, they have been canceled or limited. This mixed record complicates Iranian calculations. Credibility assessments often rely on indirect signals—troop movements, public ultimatums, deadlines, and rhetorical escalation. Such measures are intended to “tie hands” politically, signaling that leaders will suffer domestic costs if they fail to follow through.

Yet indirect signals generate their own problem: they do not reveal the true depth of resolve. An irresolute actor can mimic the behavior of a resolute one. Public threats may be interpreted as bargaining tactics rather than preparations for war. If Tehran discounts U.S. signals as coercive theater, it may resist maximalist demands, thereby narrowing the bargaining set.

Iran faces its own credibility dilemma. It threatens broad retaliation in response to U.S. bombing and promises to “fire everything it has” in a regime-survival scenario, including attacks on oil infrastructure. Limited escalation threats may be credible; total-war threats may be credible only if regime survival is clearly at stake. The ambiguity complicates American assessments.

This reciprocal uncertainty reshapes the bargaining space. Both Washington and Tehran attempt to signal resolve without triggering uncontrollable escalation. Force deployments, proxy skirmishes, and calibrated strikes are meant to clarify commitment. But deterrence theory suggests a hard truth: credibility problems are often resolved decisively only through demonstrated force in war. Empirical studies of deterrence—including Israeli cases against both state and non-state actors—indicate that victory clarifies resolve, and defeat educates. Limited exchanges may generate learning, but not decisive clarity. Absent a transformative outcome, ambiguity persists.

Maximalist threats further complicate matters. U.S. suggestions of regime change and Iranian warnings of an economic “nightmare scenario” raise systemic stakes. A regional war could remove millions of barrels of oil per day from global markets, spike prices dramatically, and trigger recession. High systemic risk can deter escalation—but it can also undermine credibility if threats appear too costly to execute. If Iran believes Washington will not risk global economic shock, it discounts U.S. resolve. If Washington believes Tehran fears regime collapse above all else, it discounts Iranian threats.

The result is a fragile bargaining environment. If U.S. threats lack credibility, Iran resists far-reaching concessions such as zero enrichment or deep missile cuts. If Iranian retaliation threats lack credibility, Washington pushes harder, further shrinking diplomatic space. But if both sides overestimate the other’s willingness to escalate, the risk of inadvertent war rises sharply.

Credibility, then, is relational and dynamic. It is not merely “resolve plus bombs,” but resolve demonstrated under risk. The danger in the current standoff is that both sides may seek incremental demonstrations of credibility—limited strikes, proxy attacks, controlled escalation—believing they can calibrate violence to avoid full-scale war. Yet escalation undertaken to prove resolve can outrun political control.

The bargaining set between Washington and Tehran exists only so long as both believe the alternative—war—is worse than compromise, and that threats are credible enough to shape concessions but not so absolute as to eliminate room for retreat. If credibility remains ambiguous, diplomacy survives. If either side concludes the other is bluffing—or that reputation now demands action—the system shifts from coercion to confrontation.

Deterrence is ultimately educational. It teaches adversaries about capability and resolve. The question facing Washington and Tehran is whether sufficient clarity can be generated through diplomacy and calibrated signaling—or whether only the brutal pedagogy of war will resolve the credibility problem.

In that sense, this crisis is not merely about enrichment levels or missile ranges. It is about whether credibility can be constructed without catastrophe.

© The Times of Israel (Blogs)