There is much to be said about the United States' decision to attack Iran - and the potential consequences of joint US-Israeli strikes on military and political targets across the country. Unfortunately, there is little to inspire optimism.
First of all, this is a war of choice. The United States had other policy options. Diplomacy seemed like a promising tool for preventing Iran from developing nuclear weapons. Increased economic pressure had the potential to eventually lead to regime change.
Moreover, this is a preventive war, not a war to preempt events. Iran did not pose an immediate threat to vital US interests. Iran was not on the verge of becoming a nuclear state or of using its existing weapons against the US. The most that can be said is that it was a gradually looming threat.
This distinction is important. A world in which states believed they had the right to preemptively attack those they perceived as a threat would be a world of frequent conflict. That is precisely why such actions have no basis in international law.
US President Donald Trump has chosen a goal - regime change - that is political, not military. But while military force can destroy and kill, it cannot in itself bring about regime change - that requires the regime to collapse. It is entirely possible that a US attack will trigger a defection within Iran's political leadership and armed forces, but that cannot be counted on. Hamas and Gaza are reminders that regimes can withstand incredible blows and still hold on to power. And even if the clerics lose power - Supreme Leader Ayatollah Ali Khamenei has been assassinated - the security forces are probably best placed to replace them.
In any case, using military force to eliminate selected leaders as a means of instigating regime change (a tactic often referred to as "decapitation") is unlikely to succeed in Iran, where the leadership has been institutionalized since it took power nearly half a century ago. In recent weeks, as the possibility of war has grown, Iranian leaders have had time to fine-tune their plans for a transition of power.
During its January incursion into Venezuela, the Trump administration limited itself to replacing a single leader (while ignoring the domestic opposition), and in most other countries around the world it has avoided democratic demands. In the case of Iran, however, Trump is calling for regime change, even though the ground is unprepared. The country’s political opposition is fragmented and has no shadow government waiting to take over, meaning it is in no position to accept “defectors,” let alone provide them with security.
History shows that regime change requires a physical presence on the ground. That is a lesson from Germany and Japan after World War II, and more recently from Panama, Iraq, and Afghanistan. And even with a physical presence, the efforts often prove insufficient. In Iran, occupation is unthinkable, given the size of the country and its capacity for resistance.
All of this suggests that the Trump administration has decided to pursue its most ambitious foreign policy goals with limited resources. It appears to have rejected a war with narrower goals, such as weakening Iran’s known nuclear and missile capabilities, even though it could convincingly claim to have achieved such goals. If there is a recent parallel to what is happening in Iran, it is Libya, where a little over a decade ago Western forces overthrew the country’s leadership with airstrikes but then withdrew, leaving the country in chaos.
It is clear that in the Iranian case, America established a military presence in the region (Trump called it an "armada"), and this ultimately forced the administration to act, because American troops there cannot be maintained on high alert forever. Therefore, the chosen means (military force) could play a significant role in determining political goals, that is, in the decision to attack. This is clearly the opposite of how decisions should be made.
Looking at the bigger picture, America has once again decided to take on a huge strategic commitment in the Middle East. This contradicts not only the National Security Strategy approved by the Trump administration itself, but also reality: the most serious challenges to US interests are in Europe and the Indo-Pacific. A parallel can be drawn here with the 2003 Iraq War - another preemptive war of choice in the same region, which proved very costly for America.
The American people are not ready for this war. And neither is Trump’s political base, because it will shake up markets, cause energy prices to spike, and could backfire. America’s allies are also concerned, because Iran has already attacked several neighboring countries and could take steps that would damage their economies. In his State of the Union address Tuesday night, Trump failed to justify attacking Iran, and his statement immediately after Saturday’s attack focused primarily on Iran’s past actions, rather than new or emerging threats.
It is possible that after last year’s cost-free bombing of three Iranian nuclear facilities and the recent intervention in Venezuela, Trump and his aides have become completely confident that they can achieve ambitious goals with limited resources and at low cost. It is also possible that Trump is eager to achieve something historic in Iran (regime change), something that his predecessors have failed to achieve. And he may yet succeed. But regime change is usually easier to call for than to successfully implement. It only takes one side to start a war, but it takes two to end it. Iran will now decide how big this conflict becomes and how long it lasts.
The author is President Emeritus of the Council on Foreign Relations; he was Director of the Policy Planning Division at the State Department (2001-2003)
Copyright: Project Syndicate, 2026.
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