WASHINGTON, D.C. — The Iranian plot to assassinate the Saudi ambassador to the United States and bomb Saudi and Israeli embassies in Washington and elsewhere was not some bizarre move by a rogue operator within Iran’s government.

It was, instead, the logical next step in Iran’s increasingly lethal war against the United States — a step demanding that Washington discard its all-too-predictable calls for greater international “isolation” for Tehran, and its reticence for confrontation, by responding with military action.

Military action need not mean full-scale war, of course, but the action must be significant enough to force the radical regime in Tehran, which clearly does not fear the United States, to take notice. Targets could include Iran’s terrorist training camps, its military sites, and key parts of its nuclear weapons program.

Having said that, military action should be teamed with stronger efforts to tighten the economic and financial noose on Iran.

Along with imposing more of its own sanctions and pushing for more European and United Nations sanctions, the United States should lead Western efforts to target in particular the Iranian Revolutionary Guard Corp (IRGC) whose Qods Force spearheaded this plot.

The IRGC is a steadily growing economic, military, and political force within the Islamic Republic. Washington can sanction multinational corporations that do business with the IRGC, and it can encourage its European allies to impose travel bans on, and freeze the assets of, IRGC leaders.

Nevertheless, U.S. military action against Iran is long overdue, and this brazen plot to launch terror on U.S. soil only strengthens the case for it.

Iran is the world’s most aggressive state sponsor of terrorism and, directly or through Hezbollah and its other terrorist minions, it has reportedly killed more Americans than any nation since Vietnam.

The attacks date to the early 1980s. Iran claimed credit for Hezbollah’s 1983 truck bombing of our embassy in Beirut, which killed 241 U.S. marines, and it was likely behind the 1996 bombing of Khobar Towers in Saudi Arabia, which killed 19 Americans.

In more recent years, Tehran’s attacks on the Americans have grown more frequent and more brazen.

In 2006, a Hezbollah-affiliated group claimed responsibility for the attempted bombing of the U.S. embassy in Caracas. A year later in Iraq, the Qods Force helped plan and execute an attack on the Provincial Joint Coordination Center in Karbala, killing five Americans and wounding three others.

In recent years, as top U.S. defense officials told Congress over the summer, Tehran has been supplying insurgents in Iraq and Afghanistan with training, other support, and arms, including improvised explosive devices (IEDs) that are responsible for growing numbers of U.S. casualties.

U.S. officials also revealed recently that Iran is working with al Qaida. The new terror plot marks neither the first time Iran has sought to launch terror in the United States — it killed a former Iranian diplomat in suburban Washington in 1980 — nor the first time that it has targeted embassies and other foreign interests around the world.

As for this new plot, efforts to label it a rogue operation are not credible.

The Qods Force is an elite group within the IRGC, which reports directly, and has sworn an oath of allegiance, to the nation’s most powerful figure, Supreme Leader Ali Khamenei. The notion that the Qods Force launched the plot with neither Khamenei’s knowledge nor approval defies credibility.

Iran has been at war with the United States ever since the 1979 Islamic Revolution catapulted a radical regime to power. It has killed Americans and aggressively sought to thwart U.S. interests in the region and beyond.

It’s time for the regime to pay a real price — one that will force its leaders to take notice — before continued U.S. reticence spurs more Iranian brazenness.

• Haas is former communications director to Vice President Al Gore and a senior fellow for U.S. foreign policy at the American Foreign Policy Council (www.afpc.org), a non-profit organization that provides scholarly information to the nation’s foreign policy experts. Readers may write him at AFPC, 509 C Street NE, Washington, DC 20002.