The alleged Israeli attack on Iran’s Embassy in Syria that killed several officials, including senior military personnel, has drawn strong condemnations and warnings of the potential for severe escalation in the already fraught regional security environment. 

The attack, if conducted by Israel as most observers believe, would mark one of the most significant strikes of a semi-secret campaign in Syria conducted by Israeli forces against suspected Iran-linked targets, sometimes referred to as “the between wars.” But as the Israel Defense Forces (IDF) now wages a full-scale war against the Palestinian Hamas movement in Gaza and faces regular attacks from groups in Lebanon, Iraq and Yemen, all eyes are on the Syrian front for how the “Axis of Resistance” may respond. 

In a letter recently obtained by Newsweek, a senior Iranian diplomat urged the United Nations to condemn the attack and warned of Tehran’s right to conduct a “decisive response." Iranian President Ebrahim Raisi vowed on Tuesday that the strike “will not go unanswered,” while Supreme Leader Ayatollah Ali Khamenei promised Israel would “regret” the move. 

The IDF declined a request to comment, in line with Israel’s traditional policy of neither confirming nor denying most operations that target the sophisticated network of Iran-linked positions in the neighboring country. 

This network is the product of the Islamic Republic’s efforts to mobilize assets in response to the rise of the Islamic State militant group (ISIS), which seized large parts of Iraq and Syria during its rapid rise a decade ago. But as the jihadis’ self-proclaimed caliphate fell to separate campaigns launched by local security forces backed by an array of actors, including Iran, Russia and the United States, Israel has feared that Iran was using its newfound presence in Syria to establish forward-operating bases and transfer weapons to allied militia across the region. 

The U.S., whose continued military presence in Syria is opposed by the government of President Bashar al-Assad, has also found its troops under fire from Iran-aligned groups. While such rocket and drone attacks have declined substantially since the deaths of three U.S. troops at the Jordan-Syria border in late January and a forceful retaliation of U.S. airstrikes in Iraq and Syria in early February, these militia retain their presence and operational capabilities. 

With both its own personnel and allies facing regular strikes by the IDF, the Iranian military announced last month, during a high-level meeting in Damascus, a new plan to deter Israeli air raids in Syria. Even prior to the uptick in tensions surrounding the war in Gaza that began nearly six months ago, Newsweek reported last year on intelligence indicating ongoing Iranian efforts to fortify air defenses in Syria, as well as the IDF’s attempts to thwart them. 

On the ground, Iran’s presence in Syria is marked by both its personnel, including members of the Islamic Revolutionary Guard Corps (IRGC), of which two commanders, General Mohammad Reza Zahedi and General Mohammad Hadi Haji Rahimi, were identified among those killed on Monday, as well as a broad array of allied actors. 

One particularly influential formation, brought to light by Newsweek’s reporting both before and after the war in Gaza erupted, is the Imam Hossein Division. Both intelligence officials and experts have described this unit, believed to be made up of thousands of fighters from across the Middle East and direct influence within the Syrian Arab Army, as the most powerful Iran-aligned force active in Syria. 

But at a time when the IDF was already mired in Gaza and warning of potential escalations across the border with Lebanon, pressure has mounted on Israeli Prime Minister Benjamin Netanyahu and his government to come up with tangible victories in the war now nearing the half-year mark, rather than expanding it. The United States, Israel’s top ally, has also stepped up its efforts to pressure Israel from pursuing a controversial offensive into Rafah and to instead focus on oft-stalled ceasefire talks. 

Washington, however, has not yet condemned the attacks on Iran in Syria, and has demonstrated its own commitment to striking Iran-linked targets in the country in the recent past, usually in direct response to attacks on its own positions. How President Joe Biden’s administration navigates the latest explosive development pushing the region to the brink of a broader war may be key in determining the course of the many, overlapping crises sparked by the ongoing conflict in Gaza. 

“We are always concerned about anything that would be escalatory or cause an increase in conflict in the region,” State Department spokesperson Matthew Miller said Monday. “It has been one of the goals of this administration since October 7th to keep the conflict from spreading, recognizing that Israel has the right to defend itself from adversaries that are sworn to its destruction.”

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