For the past year I have been writing a definitive review of US regime change policy, since 1900. Much of my research is now germane to the recent US and Israeli attacks on Iran.
When a president orders kinetic action against Iran without prior consultation with congressional leadership, the immediate battlefield may be overseas, but the enduring contest will unfold in Washington. The tension is not new. It sits at the center of the Constitution’s allocation of war powers and has shaped every major conflict of the modern era.
Article I, Section 8 of the U.S. Constitution grants Congress the power to declare war, raise and support armies, and control appropriations. Article II, Section 2 names the president Commander in Chief of the armed forces. The framers divided authority deliberately. Congress authorizes sustained war. The president directs military operations.
The friction between those clauses is structural, not accidental.
In practice, presidents have often initiated hostilities without formal declarations of war. Congress has responded episodically - sometimes by authorizing force, sometimes by restricting funding, and sometimes by acquiescing.
After Vietnam, Congress attempted to reassert its role through the War Powers Resolution of 1973. The statute requires the president to notify Congress within 48 hours of introducing U.S. forces into hostilities and limits deployments to 60 days, with a 30-day withdrawal period, absent congressional authorization. Presidents of both parties have regarded the resolution as constitutionally questionable, but they have generally complied with its reporting requirements.
Following the September 11 attacks, Congress enacted the Authorization for Use of Military Force of 2001 (Public Law 107-40).
That 60-word resolution authorized the president to use all necessary and appropriate force against those responsible for the attacks and those who harbored them. Over two decades, successive administrations interpreted it broadly to justify counterterrorism operations well beyond Afghanistan.
Congress also passed the 2002 AUMF against Iraq, which was formally repealed in 2023. The 2001 AUMF remains in force. Its continued applicability to new theaters and new adversaries remains the subject of debate.
The Supreme Court has repeatedly weighed in on the balance between executive authority and congressional limits. In Youngstown Sheet and Tube Co. v. Sawyer (1952), the Court rejected President Truman’s seizure of steel mills during the Korean War, establishing Justice Jackson’s influential framework for evaluating executive power relative to congressional authorization.
In Hamdi v. Rumsfeld (2004), the Court affirmed that the 2001 AUMF authorized detention of enemy combatants but required due process. In Hamdan v. Rumsfeld (2006), the Court limited executive authority by ruling that military commissions must comply with congressional statutes and the Geneva Conventions.
These rulings underscore a practical rule of thumb: presidential authority expands when backed by Congress and contracts when acting against it.
That dynamic matters because the War Powers Resolution is not a polite formality. Its enforcement mechanism is a clock. The 60-day period does not begin when the public hears about a strike.
It begins when the president submits the required report, or when such a report was required. Sixty days after that point, the statute states that the use of armed forces is to be terminated unless Congress declares war or enacts specific authorization. The president may extend the period by 30 days if needed for safe withdrawal. These mechanics are summarized in a Congressional Research Service War Powers Resolution backgrounder.
This clock creates incentives for legal argument. Executive branches have repeatedly tried to define certain operations as falling short of the War Powers Resolution’s triggering threshold of hostilities.
The Obama administration’s Libya position is the clearest case study. In 2011, as NATO operations continued, senior officials argued that the U.S. role did not constitute hostilities for purposes of the statute, even as U.S. forces provided enabling capabilities, as laid out in State Department testimony and debated in a Senate Foreign Relations Committee hearing transcript.
The executive branch’s internal legal framing is reflected in the OLC opinion on Libya authority (2011). That controversy became a durable reference point because it showed how the meaning of a single word can determine whether a campaign ends at day 60 or continues indefinitely.
The recent Syria precedents show a different style of legal justification. In April 2018, the Office of Legal Counsel concluded that limited airstrikes against Syrian chemical-weapons facilities could be ordered under Article II because the action served national interests and the anticipated hostilities did not rise to the level of war in the constitutional sense, as stated in OLC’s April 2018 Syria airstrikes opinion. Separate executive branch reporting has also described the 2017 Shayrat strike under Article II in the State Department report on legal frameworks for use of force.
These episodes illustrate a modern executive position: short-duration, limited-scope strikes can be justified as national interest operations even absent a new authorization.
Older precedents show how long this argument has been with us. President Truman did not seek a declaration of war for Korea in 1950, characterizing it as a United Nations police action, as described by the National Archives and by Congress’s Constitution Annotated analysis.
Kosovo in 1999 became another. President Clinton conducted a NATO air campaign without a specific authorization, amid contested congressional votes and litigation that tested the War Powers Resolution’s practical bite. Legal analysis and the contested congressional record are discussed in scholarly case studies of Kosovo and the War Powers Resolution. Each case hardened a pattern: presidents act first, then Congress chooses whether to authorize, fund, tolerate, or constrain.
Political context complicates the legal one. Midterm elections historically weaken the party holding the White House. Multiple datasets show the pattern. The long-run seat change table maintained by the American Presidency Project tracks net House and Senate changes for the president’s party across midterms.
Gallup’s historical analysis finds that presidents below 50 percent approval going into midterms have tended to experience larger House losses, as summarized in Gallup’s midterm seat-loss study.
In early 2026 polling, Reuters’ approval table places President Trump’s approval in the high 30s in mid-February, with disapproval near 60 percent in that series. Whatever one’s view of the merits of unilateral action, those numbers raise the probability of a post-election Congress that is more adversarial and more willing to use the purse and oversight as leverage.
Congress retains the power of the purse. Even if hostilities begin unilaterally, appropriations ultimately determine longevity. A change of just a few seats can flip House control. When control flips, oversight capacity and appetite rise quickly, and the president’s operational freedom narrows even if the legal posture stays the same.
The debate has intensified under the theory of the unitary executive, which emphasizes the president’s control over the executive branch and national security decision-making.
Supporters argue that decisive action deters adversaries and protects alliances. Critics warn that concentration of war-making authority risks strategic overreach and domestic fragmentation. The constitutional system forces both sides to confront the same reality: sustained campaigns require durable political consent.
A comparison with Israel is instructive because Israel operates under different constitutional mechanics and different threat geometry. Israeli strategy has long included preventive and preemptive action against weapons-of-mass-destruction pathways, often described as the Begin Doctrine after the 1981 strike on Iraq’s Osirak reactor, with archival detail collected by the National Security Archive.
Internally, Israel’s Basic Law framework concentrates war decision authority in the government and, by delegation, a smaller cabinet. In 2018, the Knesset amended Basic Law: The Government to confer authority in the matter of waging war and significant military operations through cabinet mechanisms, a shift summarized in Lawfare’s institutional review.
That structure is designed for rapid decision cycles in a small state facing proximate threats.
The U.S. structure is designed for the opposite. The American system intentionally slows the ramp to sustained war through congressional authorization and appropriations, and it invites judicial constraints when executive action departs from statutory limits.
That difference matters when U.S. leaders cite the logic of unilateral preemption. Israel can concentrate decision authority by design. The United States must navigate a separation-of-powers architecture that is designed to keep war making politically accountable and institutionally shared.
The core constitutional question today is not whether the president can act defensively. Most scholars agree that Article II permits the president to repel sudden attacks and protect U.S. forces and citizens. The harder question is duration and scope. At what point does limited defensive action become sustained war requiring fresh congressional authorization? If a strike against Iran triggers wider retaliation, the relevant issue will quickly shift from the president’s first decision to the next set of decisions about campaign objectives, tempo, and duration.
Beyond Washington, strategic calculations are layered. Israel’s recent military campaigns against Hezbollah and Hamas have reshaped regional deterrence dynamics. If Tehran perceives encirclement or regime instability, escalation risks could rise. If internal pressures mount, elite fragmentation could also alter Iran’s external posture. That environment makes miscalculation risk higher, not lower.
Advocates of decisive action argue that confronting Iranian nuclear ambitions and sanctions evasion networks earlier rather than later reduces long-term risk. They note that Venezuela’s energy trade practices and so-called ghost ship oil transfers have intersected with broader sanctions enforcement efforts, affecting revenue streams linked to Moscow and Havana.
Those effects may carry geopolitical consequences extending to Beijing, given energy market interdependence. Even sympathetic analysts, however, tend to return to the same institutional constraint: a strategy that cannot be sustained politically is a strategy that will be tested by adversaries.
Escalation management remains central. A president may initiate force quickly. Sustaining it requires alliance cohesion, intelligence integration, and congressional tolerance. History shows that military success abroad does not insulate leaders from domestic constitutional scrutiny at home.
The constitutional design assumes tension between branches. That tension is not a flaw. It is a guardrail. If hostilities expand, Congress will face a choice: authorize, restrict, or redefine the mission. The president will face another: narrow objectives or broaden them. The War Powers clock will sit behind both choices as a forcing function.
The next phase will determine whether this episode becomes a limited strike, a sustained campaign, or a catalyst for legislative recalibration of war powers.
The survival of alliances and the credibility of deterrence will depend not only on battlefield outcomes but on whether constitutional balance holds under pressure. The strategic risk is not only escalation overseas.
It is institutional