How Trump has failed to learn the lessons of the wars that followed 9/11

Trump’s Iran War Raises Old Questions From the Post-9/11 Era

Activelifezero.com – Twenty-five years after the September 11 attacks, the United States is again confronting the consequences of a president claiming broad authority to use military force without first securing Congress’ approval. President Donald Trump’s Operation Epic Fury in Iran has pushed those claims further, reviving arguments that have shadowed American foreign policy throughout the post-9/11 period.

Trump described Iran as “the world’s No. 1 state sponsor of terror,” but he began the conflict without congressional authorization, a United Nations resolution or support from NATO partners. Public backing was also limited at the outset, making it the least popular modern American war in its opening phase. The administration did not identify an immediate threat to the United States, and it did not present a convincing public plan for what would follow once fighting began.

“The world’s No. 1 state sponsor of terror”

That absence of a durable political strategy is a familiar feature of several American interventions since 2001. The United States possesses extraordinary military capabilities and can rapidly inflict damage on adversaries. Yet battlefield success does not automatically create stable political outcomes. When the use of force has drifted away from a clear end state, the result has often been prolonged instability, civilian suffering and damage to US credibility.

The expansion of presidential war powers

The attacks of September 11, 2001, initially produced a broadly supported campaign against al Qaeda and the Taliban in Afghanistan. That mission had international backing from both the United Nations and NATO allies. Over time, however, the conflict known as the war on terror widened well beyond its original focus.

President George W. Bush adopted a doctrine of preventive war that became the rationale for the 2003 invasion of Iraq. The invasion was followed by sectarian violence and civil war, during which an estimated 200,000 Iraqi civilians were killed. The disorder also helped create conditions in which ISIS later emerged.

President Barack Obama extended the use of armed drones in places including Pakistan and Yemen, countries that were not themselves at war with the United States. Those operations killed thousands of suspected militants, as well as a substantial number of civilians. Obama also authorized the 2011 intervention against Libyan leader Moammar Gadhafi with backing from the UN and NATO, though he did not obtain congressional approval.

Libya’s experience underscored the dangers of treating the removal of a government as the endpoint of a military campaign. Gadhafi’s overthrow was followed by a civil war that lasted a decade. Libya remains divided between two governments, and Obama later identified the failure to prepare for the aftermath of Gadhafi’s fall as his greatest presidential mistake.

Lessons left unlearned

The post-9/11 record contains striking operational achievements, but it also includes costly strategic failures. US intelligence and military institutions became far more effective at pursuing terrorist networks. The CIA developed substantial paramilitary capabilities. Joint Special Operations Command evolved into a highly active counterterrorism force, while Special Forces built important partnerships with Afghan and Iraqi ground troops. The National Security Agency also penetrated adversaries’ communications.

Those efforts contributed to the destruction of much of al Qaeda’s senior leadership and helped end ISIS’ territorial “caliphate.” One of the central security objectives pursued by the four presidents after 9/11 was achieved: foreign terrorist organizations did not carry out another large-scale lethal attack inside the United States.

But tactical gains did not prevent major failures in the broader conduct of war. Iraq became a warning about intervention without an accurate assessment of postwar realities. Afghanistan became another example of how military commitments can outlast the political will needed to sustain them. The agreement for a US withdrawal from Afghanistan was negotiated during Trump’s presidency and carried out under President Joe Biden. The Taliban’s return to power was a foreseeable consequence of the withdrawal.

Both episodes weakened perceptions of American competence abroad. They suggested that the United States, despite its unmatched military reach, could struggle to translate force into a coherent foreign policy outcome. That history matters when considering a war with Iran, a country whose conflict could carry significant regional and global consequences, including the possibility of economic disruption severe enough to contribute to a wider recession.

A broader definition of the war on terror

Trump had already moved to broaden the boundaries of the war on terror before the Iran operation. Last fall, he argued that suspected members of Latin American drug cartels could be targeted as “narcoterrorists.” Dozens of US strikes then hit boats carrying drugs in the Caribbean.

After US Joint Special Operations Command captured Venezuelan President Nicolás Maduro in early 2026, Trump asserted that Maduro was a narcoterrorist. The episode illustrated how a legal and political framework originally created in response to an attack by al Qaeda can be applied to new enemies and new categories of alleged threats.

The central issue is not whether the United States has the capacity to strike its adversaries. Its modern counterterrorism institutions have repeatedly demonstrated that capacity. The harder question is whether military action serves a defined national objective, has legitimate political support and includes a credible plan for the consequences that follow.

Iran has placed those questions at the center of American politics again. The last quarter-century shows that presidents can steadily accumulate authority to order force across borders. It also shows that starting a war is far easier than managing the political, humanitarian and economic consequences after it begins.