There's been a theme this week. On Thursday, the U.S. carried out a deadly drone strike against a militia group in Baghdad. A day earlier, the U.S. threatened tougher action against Houthi rebels in Yemen. And on Tuesday, a Hamas leader was killed in a drone strike in Beirut.
The thread that ties these events together is Iran and its proxies. All these attacks or warnings are directed at Iran's broad network of militant groups that are spread across the Middle East.
Iran has overseen a range of hardline factions for decades, and these groups have stepped up attacks over the past three months, ever since Hamas, a leading beneficiary of Iranian support, launched its assault on southern Israel on Oct. 7.
Today, Iran supports groups attacking U.S. and Israeli forces in five separate places in the Middle East, according to U.S. and Israeli officials.
Iran backs Hamas in the Israel-Gaza war. Iran supports Hezbollah in the daily rocket and missile exchange along the Israel-Lebanon border. Iran arms the Houthis, who are firing at commercial cargo ships, which are being protected by the U.S. Navy. And Iran is also the patron of smaller militias that have attacked U.S. troops repeatedly in Iraq and Syria, mostly with drones.
Iran seeks to weaken Israel, oust the U.S.
Iran's longstanding goals are to undermine Israel and to drive U.S. forces out of the region. By design, Iran, a Persian nation, pursues this agenda with Arab proxy forces so Tehran can maintain an arm's length and not get directly involved in the fighting.
Iran has "very cautiously unleashed the whole network of armed gangs that they run in the Arab world that it calls 'the axis of resistance,'" said Hussein Ibish of the Arab Gulf States Initiative in Washington.
Tehran wants "to use proxies in order to engage on various battlefields without it ever touching Iran or Iranians or without it coming close to the homeland," he added.
However, there's been a shift in recent days. There's still no indication that Iran could become directly involved in any of the hostilities. But the U.S. has taken military action, and warned of further steps, that go beyond what's taken place the past three months.
Consider the U.S. drone strike in Baghdad, which killed three members of the group Harakat al-Nujaba in a car outside an Iraqi security building. The faction is on a list of U.S. terrorist groups.
Still, a U.S. attack inside Iraq is out of the ordinary these days. Iraq is hosting the U.S. forces and an Iraqi government spokesman called the U.S. strike a "flagrant violation of the sovereignty and security of Iraq."
In the region's complicated web of relationships, the militia that the U.S. struck has ties to Iraq's security forces, and it's also backed by Iran, according to the Americans.
The U.S. airstrike took place after American troops at remote bases in Iraq and Syria have come under attack more than 100 times in recent weeks by various militants backed by Iran.
Houthi attacks on international shipping
In addition, the White House issued a warning Wednesday that it was prepared to step up action against the Houthis in Yemen.
"The Houthis will bear the responsibility of the consequences should they continue to threaten lives, the global economy, and free flow of commerce in the region's critical waterways," the statement said.
Iran has armed the group for years in Yemen's brutal civil war. Since November, the Houthis have been firing drones and missiles, and employed small attack boats against commercial cargo ships in the Red Sea off the southwest coast of Yemen.
The U.S. Navy has intervened to beat back most of these attacks. But major commercial shippers, like Maersk, are now avoiding the Red Sea and taking a much longer and more expensive trip around the southern tip of Africa.
The U.S. says Iran is providing the Houthis the weapons for these attacks, though Iran denies such involvement.
"If Iran didn't want the Houthis threatening maritime security in the Red Sea, they would have made that clear in one way or another, and the Houthis would have cut it out, but they haven't. So obviously, at a minimum, Iran is supportive of this," said Ibish.
The risk of an Israel-Hezbollah escalation
When regional tensions flare up, Israel and Hezbollah are prone to trade rocket and missile fire across the Israel-Lebanon border. But these exchanges have unwritten rules. Both sides often limit the shooting to areas near the border and seek to avoid escalation that could lead to full-scale fighting.
Most analysts say this has been the case the past couple months, in part because Lebanon is in an economic crisis, and Israel is preoccupied with the war in Gaza. But a drone strike on Tuesday killed a senior Hamas leader, Saleh al-Arouri, while he was at a meeting in Lebanon's capital Beirut.
Israel has not said whether it carried out the attack, but it has stated it would go after Hamas leaders wherever they might be in the wake of the Oct. 7 Hamas attack. If Israel was responsible, this would mark the first time it struck such a high-ranking Hamas figure in a foreign capital, raising the prospect of additional high-profile strikes.
"If the enemy considers waging a war against Lebanon, our battle will be without boundaries or rules," Hezbollah leader Hassan Nasrallah said Wednesday. "We are not afraid of war. Those who think of going to war with us will regret it. War with us will come at a very, very, very high cost."
Iran's proxies disrupt, but haven't scored decisive gains
The current Middle East turmoil demonstrates how disruptive Iran and its proxies can be. But this doesn't mean Iran has achieved its larger regional goals.
Ironically, President Biden and his two predecessors, Donald Trump and Barack Obama, have all sought to shrink the U.S. military footprint in the Middle East. Yet recurring conflicts keep drawing the U.S. back in.
Also, Israel expanded diplomatic relations and trade ties with Arab countries in recent years despite the Iranian efforts to counter any such moves.
In addition, the places where Iran has been most deeply involved are in crisis. They include Gaza, which has been run by Hamas. Lebanon, where Hezbollah is the leading powerbroker. And Yemen, where the Houthis are the dominant force.
Still, Hussein Ibish believes Iran's takeaway from recent events is that the various groups increase Tehran's influence throughout the region.
"It's reinforced Iran's commitment to using proxy groups in the Arab world to get essentially fanatical Arabs to fight their wars for them," he said.
Greg Myre is an NPR national security correspondent who has reported extensively from the Middle East. Follow him @gregmyre1.