The debate over sequestration is focused nearly entirely on the impact of spending reductions on the U.S. economy. Far less attention is given to how the automatic spending cuts would undermine the credibility of American power abroad. As sequestration comes into force, the White House and Congress signal a dangerous lack of resolve to both allies and adversaries. In doing so, they run the risk that a nervous Israel and an adventurous Iran could plunge the Mideast into a war the United States can ill afford.

U.S. defense officials warn that sequestration’s $43 billion cuts to U.S. defense spending in 2012 would “hollow out” the armed forces and reduce readiness. Already, sequestration has forced the U.S. Navy to cut the number of deployed aircraft carriers in the Persian Gulf from two to one and reduce training of active duty soldiers. Recently retired Secretary of Defense Leon Panetta alerted civilian Pentagon staff that sequestration may require them to take one day per week of unpaid leave. These steps would certainly harm U.S. national security. But ultimately, their true impact on the defense capabilities of the United States is difficult to quantify.

Sequestration’s real harm is the damage it poses to American credibility abroad. The ability of a superpower to deter enemies and reassure allies is a product not just of its raw power, but also its willingness to exercise it. In allowing sequestration to occur, the president and Congress will demonstrate a bipartisan willingness to sacrifice U.S. defense interests in order to achieve tactical political gains. This has important implications for Washington’s friends and enemies alike.

No two countries are watching the charade of sequestration more closely than Israel and Iran. The timing of sequestration is particularly unfortunate for President Obama, who will make his first visit as U.S. president to Israel in March. The goal of his trip is to reassure Prime Minister Benjamin Netanyahu that the United States will not allow Iran to obtain a nuclear weapon, including through use of military force if necessary. In doing so, Obama hopes to convince the Israelis not to launch a preemptive strike against Iran’s nuclear facilities that could plunge the United States into a regional conflict. Netanyahu will only launch a unilateral strike if he doubts the credibility of U.S. willingness to use force against Iran. The nonchalance of the president and Congress in the face of sequestration undermines U.S. credibility with Israel in advance of Obama’s visit to a key ally and increases the risk of an Israeli strike on Iran.

Iran will draw its own conclusions from sequestration. The mullahs already had reason to question Obama’s willingness to use force to back up his words, given his reluctant intervention in Libya in 2011 and refusal to use force in Syria. Sequestration will only strengthen doubts in Iran that Washington is unwilling and unable to enforce its stated nuclear redlines. It will bolster hardliners in Tehran and weaken doves who want a settlement with the West on Iran’s nuclear program. Yet at precisely the moment a negotiated outcome faces its last, best hope of success, the U.S. political class has undermined its diplomats with a message of weakness.

History is full of cases when an emboldened power uses misguided beliefs about the weakness of its rival to engage in risky behavior. The Cuban missile crisis is the best example, when mistaken Soviet assumptions about the mettle of President Kennedy pushed the world to the brink of nuclear war.

In light of sequestration, the United States should expect similar assertiveness from Iran. Strident rhetoric aside, Iran’s back is against the wall. Its economy has been battered by western sanctions, the political class is engaged in fierce infighting, and its Syrian ally is on the verge of collapse. Iran’s embattled leaders may conclude that there is much to be gained and little to be lost from an uncompromising attitude on its nuclear program and adventurous behavior in a fluid Middle East.

A superpower like the United States cannot hold its military power hostage for domestic political advantage without squandering its global credibility and risking its security. The world is watching Washington’s dysfunction and planning accordingly. If the United States wants to reduce the likelihood of war in the volatile Middle East, it will act now to roll back sequestration and signal bipartisan support for a strong national defense.

Jeff Lightfoot is deputy director of the Brent Scowcroft Center on International Security at the Atlantic Council.