(Jerusalem Center for Security and Foreign Affairs) Earlier this month, President Donald Trump acted on his threat to retaliate against Islamic State following the killing of three Americans—two soldiers and a civilian interpreter—in a terrorist attack carried out by an ISIS operative in the city of Palmyra, in the Syrian desert, on Dec. 13.

As part of the response, U.S. military aircraft struck approximately 70 ISIS targets on Dec. 19 in the desert areas of Deir ez-Zor, Homs and Raqqa. Jordanian Air Force jets also took part in the aerial campaign.

While Trump described the operation as “a very powerful act of revenge,” U.S. Defense Secretary Pete Hegseth stated, “American forces have launched ‘Operation Hawkeye Strike’ in Syria, aimed at eliminating ISIS fighters, infrastructure and weapons storage sites.”

He defined the operation as a “retaliatory message” following the Palmyra attack. Sources close to the Syrian Defense Ministry indicated that the U.S. strikes could continue for several days.

Syria is marking one year since the fall of Bashar Assad’s regime. Interim President Ahmed al-Sharaa now faces the decisive test of his rule—the fight against ISIS, alongside the parallel effort to turn a fragmented Syria into a unified state.

Senior Israeli security officials say that the Dec. 13 ISIS attack on U.S. troops has alarmed both Washington and Jerusalem and underscores the magnitude of the security challenge confronting al-Sharaa.

According to Syrian media, ISIS has attempted twice in recent months to assassinate al-Sharaa.

Despite the overthrow of Assad’s regime, Syria’s social fractures have not healed.

Within this vacuum, ISIS has found fertile ground for action. ISIS is highly familiar with the terrain, the population and the regime itself, particularly al-Sharaa. Many of its operatives emerged from the same regions in Syria; some previously fought within factions that later disbanded or were absorbed into the new reality.

The new Syrian regime’s security forces launched a broad wave of arrests of ISIS operatives following the Palmyra attack. They speak of close surveillance of suspected ISIS activity, name-based watch lists and targeted neutralizations of operatives.

Thousands of armed young men

Israeli security officials note that al-Sharaa seeks to present himself as the president of a state, not as the commander of Hayat Tahrir al-Sham, the Sunni Islamist group that he headed. However, the transition from revolutionary-military rule to institutionalized sovereignty requires change not only at the top of government but also at the grassroots level.

Syria has thousands of armed young men lacking formal education, stable livelihoods or a civilian future, an ideal recruitment pool for ISIS. The danger is clear—without frameworks for absorption, rehabilitation and integration into state life, these young men could become a reservoir of manpower for ISIS, driven by ideology or despair.

For the United States and Israel, the campaign against ISIS has become a central litmus test for the credibility of the new regime in Damascus. From Washington’s perspective, al-Sharaa’s ability to restrain, dismantle and eradicate the remnants of the organization serves as a practical criterion for determining whether Syria is truly leaving the era of terrorism behind, or merely changing symbols and rhetoric.

Israeli security officials say the Palmyra attack on U.S. forces marked a turning point. In Washington, it was perceived not as an isolated incident but as proof that ISIS retains the ability to initiate attacks, penetrate defenses and deliver a dual message—undermining internal stability while signaling outwardly that the Syrian arena remains active for terrorism despite the change of regime.

Since the attack, American pressure on Damascus has shifted from declarative rhetoric to demands for results.

The Trump administration conveyed a clear message to al-Sharaa that it wants to see arrests, dismantling of infrastructure and effective control over desert regions and peripheral areas.

The security balance in the north

For Israel, ISIS is not the direct and immediate threat in the classic sense, but a dangerous catalyst for destabilizing the security balance in the north. On Dec. 19, IDF troops arrested an ISIS operative in southern Syria who was planning attacks against Israel.

In Israel, the organization is viewed less as a standalone target and more as a symptom, an indicator of a prolonged governance vacuum in Syria that could rapidly spill over to the Golan Heights and threaten Israeli communities.

From the Israeli perspective, every significant ISIS attack, especially the one in Palmyra, is a reminder that the Syrian space remains porous. Areas not under effective control of the central government in Damascus could become not only havens for Sunni terrorism but also corridors of activity for Shi’ite Iran and its proxies.

The concern within Israel’s security establishment is a familiar dynamic: where governance is weak, radical actors enter, whether in the name of Sunni jihad or under the banner of Shi’ite “resistance.”

Israel’s primary concern is not only ISIS as a cross-border organization, but the possibility that the chaos it generates will be exploited by Hezbollah and pro-Iranian militias to deepen their foothold in southern Syria.

A security vacuum in the Palmyra region, the Syrian desert and the east-west transit routes is perceived in Israel as a complementary link in the Iranian axis, one that enables movement, smuggling and the establishment of terrorist infrastructure on the ground.

The Palmyra attack reinforced Israeli assessments that al-Sharaa’s regime is still struggling to impose genuine sovereignty, and that declarations of war on ISIS are no substitute for actual control of territory.

Any Syrian failure to eradicate the organization is viewed in Israel not merely as an internal problem for al-Sharaa’s rule, but as a regional risk that could directly affect the Golan border and Israel’s freedom of action in the northern arena.

This underpins Israel’s skepticism toward international reconstruction and stabilization processes in Syria. As long as ISIS can strike deep inside the country, and as long as Iran identifies opportunities to exploit instability, Syria will remain, in Israel’s eyes, a volatile arena rather than a restraining actor.

Within Israel’s security establishment, assessments of al-Sharaa’s chances of success in the war against ISIS are sober and even skeptical.

The prevailing assumption is that the new Syrian regime can contain a broad expansion of the organization and strike its overt cells, but will struggle greatly to eradicate ISIS’s deep infrastructure in the Syrian desert and remote tribal regions.

According to Israeli security assessments, al-Sharaa’s success depends not only on political determination or tough declarations, but on three critical conditions: effective territorial control beyond the main cities; sustained intelligence and operational cooperation with the United States; and the setting of clear limits on Iranian influence and the activity of Shi’ite militias, which undermine the Sunni legitimacy of the fight against ISIS.

In Israel, it is believed that as long as al-Sharaa attempts to wage a dual struggle, against ISIS on the one hand and against external actors such as Iran on the other, his ability to achieve a decisive victory will remain limited. A more plausible scenario, from the Israeli viewpoint, is that he will “manage the threat” rather than eliminate it, conducting targeted strikes, curbing ISIS’s freedom of action, but falling short of completely eradicating its presence in Syria.

Israel does not rule out the possibility that al-Sharaa may succeed in stabilizing Syria at a basic level, but at this stage sees no conditions that would enable him to defeat ISIS in an unequivocal victory.

Originally published by the Jerusalem Center for Security and Foreign Affairs.