Why Any U.S.-Iran Peace Agreement Depends on Lebanon
For Tehran, lasting peace with the United States does not run solely through direct negotiations with Washington. There is another critical link: Lebanon.
If the ceasefire in Lebanon is not stabilized, any agreement between Iran and the United States will be temporary, fragile, and lacking any real guarantee.
1. Lebanon: The Front Line Backed by Iran
Israel’s security doctrine after October 7 shows that war in Lebanon is a prelude to the next attack on Iran. Israel wants to neutralize the northern front first and then, with a freer hand, place a direct attack on Iran on the agenda.
For this reason, stopping Israel in Lebanon is not only a matter of defending a regional ally. It is part of Iran’s preemptive defense of its own security. If Iran can stop Israel in Lebanon, it will, in practice, have reduced the likelihood of another attack on Iranian territory.
2. Multi-Front War: Israel’s Vulnerability
In the 40-day war, the simultaneity of Hezbollah’s pressure from the north and Iran’s attacks had a decisive effect: it saturated Israel’s air defenses. The issue was not simply the number of missiles; it was the multiplicity of fronts. When Israel is forced to face threats simultaneously from the north and the east, the cost of war rises and its capacity for strategic focus declines.
According to a report by Haaretz, in the final weeks of this conflict, the hit rate of Iranian missiles had reached around 80 percent—a figure that would not have been achievable without simultaneous pressure from Hezbollah. It was this compounded pressure that pushed Israel toward a ceasefire with Iran. Israel prefers not to become trapped in two attritional fronts at the same time. But if it first secures the Lebanon front, the calculation of another attack on Iran will become easier.
3. The Question Every Agreement Must Answer
Iran faces a fundamental question: if the United States cannot or will not restrain Israel in Lebanon, what guarantee is there that, after a diplomatic agreement, it can prevent another Israeli attack on Iran?
This is not only a diplomatic question; it is the fundamental question behind any security agreement. An agreement has meaning only when the other side can control the behavior of its ally. But the record of recent wars in the region has shown that the United States lacks the willingness or ability to restrain Israel in military operations.
The logical conclusion is clear: any agreement that removes Lebanon from the equation is one-sided. Iran gives concessions and receives no enforceable guarantee. If the United States wants peace with Iran, it must show that peace means not only a temporary pause in fighting on the Iran front, but also restraining the cycle of war across linked fronts.
Otherwise, Iran will use its pressure tools—including the Strait of Hormuz—to compel the United States to do so. The message is clear: if the United States does not want to restrain Israel, Iran will try to raise the cost of failing to restrain Israel.
4. Iran’s Strategic Credibility
The next issue is Iran’s credibility among its regional allies.
Hezbollah paid a heavy price in the recent war and, in practice, took some of the pressure of the war off Iran. But between March 2024 and March 2025, when Hezbollah was under the heaviest Israeli military pressure, Iran did not directly enter the conflict before the assassination of Hassan Nasrallah. If the perception takes hold that Tehran abandons its allies at moments of danger, the consequences will go beyond Lebanon. This message will also reach Yemen, Iraq, and other components of the Axis of Resistance.
The Houthis in Yemen impose costs on the United States and its allies when they believe that Iran, too, stands behind its allies at moments of crisis. They control the Bab el-Mandeb Strait—a strait that, if closed simultaneously with Hormuz, would multiply the economic blow to the West. This is one of the factors that has helped remove Washington’s incentive to escalate the war with Iran. But this leverage is effective only when Iran’s network of allies feels that it is part of a real alliance, not a disposable tool to be used when needed.
For Iran, maintaining credibility among its regional allies is not merely a political or moral issue; it is part of its deterrence architecture.
Therefore, a ceasefire in Lebanon serves three functions for Tehran at once:
First, it preserves Hezbollah as a nearby lever of pressure against Israel and keeps the cost of any future attack high.
Second, it tests America’s real capacity and willingness to restrain Israel—a test that any future agreement must pass.
Third, it preserves the cohesion of Iran’s regional network of allies and its deterrent capability.
Without Lebanon, any agreement with the United States will lack guarantees and remain unstable.
Thanks for reading! Subscribe for free to receive new posts and support my work.