Neither Washington nor Tehran want the conflict in Gaza to spark a larger war in the region, officials in both capitals say.
But in the seven weeks since the Hamas-led attack on Israel on October 7, Iran-backed militias have launched more than 70 rocket and drone attacks against US troops in Iraq and Syria. The Pentagon, for its part, responded with four air strikes that killed up to 15 people, according to US officials.
National security officials fear that a miscalculation in the face of mutual attacks, combined with each side’s belief that the other doesn’t want a major fight, could trigger just that: a regional conflict just two years after the United States ended the 20-year war in the Middle East and South Asia.
So far, none of the U.S. retaliatory strikes have escalated, including last week’s in Iraq that killed several militants from Kataib Hezbollah, an Iran-backed group. The Pentagon said on Tuesday that attacks had at least temporarily eased – most recently on November 23, a day before an operational pause in the Gaza war began.
But American military commanders and intelligence agencies continue to closely monitor Iran and the groups it supports, which include Hezbollah in Lebanon, the Houthis in Yemen and militias in Iraq and Syria. A Navy warship shot down a drone fired from Yemen in the southern Red Sea on Wednesday that a U.S. military official said posed a threat to the ship.
“The problem with people’s view is that we were only thinking about a short war in Gaza,” said Vali Nasr, an Iran expert and professor of international affairs and Middle Eastern studies at Johns Hopkins University.
But, he said, Iran and Hezbollah believe that once Israel is done with Hamas, it will turn its attention to them.
“If the United States is not careful, Gaza is just the beginning of something much, much bigger,” Nasr said.
Defense Department officials believe Iran is using the militias’ attacks to warn the United States about what would happen to American troops and interests in the region if Israel expands its campaign against Hezbollah, or if Israel does as in in the past has targeted Iran’s nuclear program.
Since the start of the war, there have been repeated clashes between Israel and Hezbollah along Israel’s northern border with Lebanon. A US official said the Biden administration wants Israel to “turn away” from the clashes. However, the official did not elaborate on what the government was doing to stop Israel from starting a two-front war.
The official spoke on condition of anonymity to discuss private conversations with Israeli officials.
Since the beginning of the conflict, Tehran and Washington have exchanged several messages saying that neither side wants to escalate the war, Iranian Foreign Minister Hossein Amir Abdollahian said in an interview.
“We understand that the US does not want the war to expand, but we believe that the US wants the war to worsen,” Amir Abdollahian said. “If the United States continues to support Israel militarily, politically and financially and to help address Israel’s military attacks on Palestinian civilians, it will face the consequences.”
Since the October 7 attacks, intelligence officials have been briefing President Biden on the threat of a major war with Iran. For weeks, secret services have been assuming that Iran wants to avoid a major conflict – an assessment that still applies, at least for the time being.
Guided by this intelligence, US defense officials proposed targeted retaliation against Iranian-backed militias in Iraq and Syria following drone strikes on military bases. As the White House considered the options, Avril D. Haines, the director of national intelligence, and Mr. Biden discussed the possible outcomes.
The Biden administration publicly states that its strategy is one of deterrence.
After the Hamas attacks, the Pentagon tried to send that deterrent message by deploying two aircraft carriers and accompanying warships — one to the eastern Mediterranean, the other near the Persian Gulf — as well as a Marine Corps amphibious task force and dozens of additional fighter jets .
But U.S. officials blame Iran and its allied militias for repeated missile and drone attacks on U.S. forces in Iraq and Syria.
American warplanes struck ammunition depots in eastern Syria on October 27 and again on November 8. The Pentagon concluded that there were no casualties in these attacks.
On November 12, American airstrikes on facilities of Iran’s Islamic Revolutionary Guard Corps and its proxies in eastern Syria killed six or seven people. One attack hit a large ammunition bunker that Pentagon officials said provided weapons for recent attacks.
“Our attacks have significantly downgraded and impaired these militia groups’ access to these weapons,” Sabrina Singh, a Pentagon spokeswoman, said at the time.
Biden administration officials say the targeted attacks are intended to harm Iran and its proxies without triggering a regional war that would involve the United States. Mr. Biden has rejected more aggressive bombing campaigns in recent weeks, senior military officials said.
“Our main goal is to contain this conflict in Gaza and ensure that it is contained,” Ms. Singh said earlier this month. “Right now that’s where we see it. We see that the conflict within Israel and the Gaza Strip and between Israel and Hamas remains.”
American intelligence agencies say this approach is working so far.
“Even if the United States is attacked, we expect Iran and Hezbollah to try to walk a very fine line in the region and avoid overt actions that risk pushing them into more direct conflict with Israel or the United States “They incur costs by enabling anti-U.S. and anti-Israel attacks,” Christine Abizaid, director of the National Counterterrorism Center, told the House Homeland Security Committee on Nov. 15.
The question, the officials say, is whether Mr. Biden can stop Israel from expanding the conflict.
Some Republicans in Congress complain that the U.S. military response has been inadequate and has even led Iran and its proxies to take more aggressive actions.
Defense Secretary Lloyd J. Austin III and Mr. Biden “may not want to seek conflict, but Iran does, and it will continue to try to kill our troops until they face real consequences, until they face real fear,” Senator Tom Cotton, an Arkansas Republican and a member of the Armed Services Committee, said in a speech on the Senate floor.
“Iran will not fight if we jeopardize the things it cares most about: its shock troops in the Iranian Revolutionary Guard Corps, the Quds Force or, if necessary, sites and facilities within Iran itself,” Mr. Cotton said .
The United States has 2,500 troops in Iraq and 900 in Syria, mostly to help local forces fight remnants of the Islamic State.
More than 60 U.S. soldiers in Iraq and Syria have suffered injuries in attacks by Iran-backed militias, about half of them traumatic brain injuries. Pentagon officials say all troops are now back on duty.
But senior U.S. military officials say only luck saved the United States from major losses. A drone loaded with explosives landed in a barracks at Erbil Air Base in Iraq on October 25. It turned out to be an unexploded bomb, but an explosion would most likely have injured or killed several military personnel, a senior military official said.
Farnaz Fassihi contributed reporting from New York.