On Sunday, February 11, Iran marked the 45th anniversary of the 1979 Islamic Revolution amid tensions gripping the wider Middle East over Israel’s continued war with Hamas in the Gaza Strip.

The Islamic Revolution began with widespread unrest in Iran over the rule of Shah Mohammad Reza Pahlavi. The shah, terminally and secretly ill with cancer, fled the country in January 1979. Ayatollah Ruhollah Khomeini then returned from exile and the government fell on February 11, 1979, after days of mass demonstrations and confrontations between protesters and security forces.

In the anniversary celebrations, thousands of Iranians marched through major streets and squares decorated with flags, balloons and banners with revolutionary and religious sayings. In Tehran, crowds waved Iranian flags, chanted slogans and carried placards with the traditional “Death to America” and “Death to Israel” written on them. Some burned U.S. and Israeli flags, a common practice in pro-government rallies.

Processions started out from several points, converging at Azadi Square in the capital. State TV showed crowds in many cities and towns, claiming that “millions participated in the rallies” across the country. The military displayed a range of its missiles, including the Qassem Soleimani and Sejjil ballistic missiles, the Simorgh satellite carrier and drones at the square where people took selfies with them. During the celebrations, a paratrooper jumped from a plane while displaying a Palestinian flag.

Many high-ranking Iranian officials attended the celebrations in Tehran, including hardline President Ebrahim Raisi. He addressed the crowds in Azadi Square and called on the United Nations—in a speech broadcast by state TV—to expel “the Zionist regime,” as the crowds chanted: “Death to Israel.” Mr. Raisi also said, “The bombing of Gaza has to be stopped as soon as possible.”

Yet contrary to the spectacle of these celebrations, Iran’s involvement in the Mideast conflict has so far been indirect. The involvement of the Persian nation has so far largely been through proxies, which consist of a number of militia groups in various regions. As America and its allies combat these groups, the specter of a larger Middle East war looms large.

Militias in Action

The proxy groups backed by Iran have been waging attacks on Israeli and U.S. targets since war erupted between Iran’s Palestinian ally Hamas and Israel on October 7. The campaign has prompted U.S. counterstrikes and fueled fears of a wider escalation. These groups have been called Iran’s “Axis of Resistance.”

In early January, a drone attack killed three U.S. troops in Jordan, which an umbrella group for Iran-backed factions known as the Islamic Resistance in Iraq claimed. The U.S. said it held Tehran responsible. Iran threatened to “decisively respond” to any U.S. attack on the Islamic Republic. Washington then responded with airstrikes against Iranian-linked targets in Syria and Iraq. There are several key groups involved.

The Islamic Resistance in Iraq is an umbrella group of hardline Shiite Muslim armed groups close to Iran. This group claimed an attack near the Syrian-Jordanian border around the same time U.S. officials said their troops were targeted. They have claimed more than 150 attacks on bases housing U.S. forces in Syria and Iraq since October, leading to dozens of mostly minor injuries and drawing several rounds of U.S. strikes in response.

Iranian-backed Shiite groups emerged as powerful players in Iraq after the 2003 U.S.-led invasion, with tens of thousands of fighters.

While members of these armed groups receive state salaries and are technically under the authority of the prime minister, they often operate outside the chain of command.

Those targeting U.S. forces in recent months include Kataib Hezbollah and the Nujaba group, both of which are closely linked to Iran’s elite Revolutionary Guards. Their arsenal includes explosive drones, rockets and ballistic missiles.

Their statements have declared the operations as part of an effort to “resist American occupation forces in Iraq and the region,” and carried out in “response to the massacres” committed by Israel against Palestinians in Gaza. The groups are designated terrorist organizations by the United States.

The Houthi movement, which controls large parts of Yemen, announced it had entered the conflict on October 31, firing drones and missiles at Israel more than a thousand miles from their seat of power in Sanaa.

In November, the Houthis expanded their role by attacking shipping in the southern Red Sea, saying they were targeting vessels belonging to Israelis or heading to Israeli ports—though some of the targeted ships had no known Israeli links.

The campaign prompted the United States and Britain to launch air strikes against Houthi targets in Yemen in January. The Houthis declared all U.S. and British ships and warships taking part in “the aggression” would be targets for the group.

The attacks have disrupted international commerce on the shortest shipping route between Europe and Asia, leading some shipping companies to reroute their vessels.

The United States believes Iran’s Revolutionary Guards (IRGC) have been helping to plan and carry out the Houthi missile and drone attacks. Iran denies involvement. Sources told Reuters in January that commanders from the IRGC and Hezbollah are on the ground in Yemen helping to direct and oversee Houthi attacks on Red Sea shipping. The Houthis have denied any Hezbollah or Iranian involvement.

The United States returned the Houthis to its list of designated terrorist groups in response to the shipping attacks.

The heavily armed Lebanese group Hezbollah has been mounting near-daily attacks on Israeli targets at the Lebanese-Israeli border since October 8, prompting the heaviest exchanges of fire between the enemies since they waged full-scale war in 2006.

Hezbollah says its attacks have helped to stretch the Israeli army while also uprooting tens of thousands of Israelis who have fled homes near the border. Israeli air and artillery strikes have also forced tens of thousands of Lebanese to flee.

Agence France-Presse reported: “The cross-border hostilities have killed at least 281 people on the Lebanese side, most of them Hezbollah fighters but also including 44 civilians, according to an AFP tally. On the Israeli side, 10 soldiers and six civilians have been killed since October, according to the Israeli army.”

A U.S. envoy has been engaged in efforts to prevent the violence from spiraling into an even bigger conflict.

Founded by Iran’s Revolutionary Guards in 1982, Hezbollah has served as a model for other Tehran-backed groups across the region and has also advised or trained some of them.

Hezbollah is widely regarded as more powerful than the Lebanese state and shares Iran’s Shiite Islamist ideology. The United States designates Hezbollah as a terrorist organization.

America’s Warning

After retaliatory strikes, the United States warned Iran and the militias it arms and funds that it will conduct more attacks if American forces in the Mideast continue to be targeted, but that it does not want an “open-ended military campaign” across the region.

“We are prepared to deal with anything that any group or any country tries to come at us with,” said Jake Sullivan, President Joe Biden’s national security adviser. Mr. Sullivan said Iran should expect “a swift and forceful response” if it—and not one of its proxies—”chose to respond directly” against the U.S.

“We cannot rule out that there will be future attacks from Iranian-backed militias in Iraq and Syria or from the Houthis,” Mr. Sullivan said. He said the president has told his commanders that “they need to be positioned to respond to further attacks as well.”

Mr. Biden “is not looking for a wider war,” Mr. Sullivan said, when questioned about the potential for strikes inside Iran that would expand the conflict in the volatile region. But when asked about the possibility of direct escalation by the Iranians, he said: “If they chose to respond directly to the United States, they would be met with a swift and forceful response from us.”

While pledging to respond in a “sustained way” to new assaults on Americans, Mr. Sullivan said he “would not describe it as some open-ended military campaign.”

Still, he said, “We intend to take additional strikes and additional action to continue to send a clear message that the United States will respond when our forces are attacked or our people are killed.”

There will be more steps taken, he said. “Some of those steps will be seen. Some may not be seen.”

January’s attack by the U.S. on dozens of sites in Iraq and Syria hit more than 85 targets at seven locations. These included command and control headquarters, intelligence centers, rockets and missiles, drone and ammunition storage sites and other facilities that were connected to the militias or the Islamic Revolutionary Guard Corps’ Quds Force, the expeditionary unit that handles Tehran’s relationship with, and arming of, regional militias.

The Biden administration has so far appeared to stop short of directly targeting Iran or senior leaders of the Quds Force within its borders.

The U.S. military did not have any confirmation of civilian casualties from those strikes, Mr. Sullivan said. “What we do know is that the targets we hit were absolutely valid targets from the point of view of containing the weaponry and the personnel that were attacking American forces. So, we are confident in the targets that we struck.”

Some of the militias have been a threat to U.S. bases for years, but the groups intensified their assaults in the wake of Israel’s war with Hamas following the October 7 attack. The Houthis have made clear that they have no intention of scaling back their campaign despite a new international force to protect vessels in the vital waterway.

U.S. strikes in January struck across six provinces of Yemen held by the Houthi rebels, including in Sanaa, the capital. The Houthis gave no assessment of the damage, but the U.S. described hitting underground missile arsenals, launch sites and helicopters used by the rebels.

“These attacks will not discourage Yemeni forces and the nation from maintaining their support for Palestinians in the face of the Zionist occupation and crimes,” Houthi military spokesman Brigadier General Yahya Saree stated.

“The aggressors’ airstrikes will not go unanswered,” he said.

Meanwhile, Iran warned the U.S. over potentially targeting two cargo ships in the Mideast long suspected of serving as forwarding operating bases for Iranian commandos. The statement from Iran on the Behshad and Saviz ships appeared to signal Tehran’s growing unease over the U.S. strikes across the region.

The ships are registered as commercial cargo ships with a Tehran-based company the U.S. Treasury has sanctioned as a front for the state-run Islamic Republic of Iran Shipping Lines. The Saviz, then later the Behshad, have loitered for years in the Red Sea off Yemen, suspected of serving as spy positions for Iran’s Revolutionary Guard.

In a video statement by Iran’s regular army, a narrator describes the vessels as “floating armories.” The narrator describes the Behshad as aiding an Iranian mission to “counteract piracy in the Red Sea and the Gulf of Aden.” But Iran is not officially known to have taken part in any of the recent campaigns against rising Somali piracy in the region off the back of the Houthi attacks.

Just before the new campaign of U.S. airstrikes began, the Behshad traveled south into the Gulf of Aden. It docked in Djibouti in East Africa just off the coast from a Chinese military base in the country.

The statement ends with a warning overlaid with a montage of footage of U.S. warships and an American flag.

“Those engaging in terrorist activities against Behshad or similar vessels jeopardize international maritime routes, security and assume global responsibility for potential future international risks,” the video said.

As these proxy groups continue to cause trouble and America strives to show a measured response, keep your eye on what is happening. Time will tell whether the conflict between the U.S. and these proxy groups will explode into a larger war involving Iran itself.

This article contains information from Reuters and The Associated Press.