Israel‘s military operation against Iran‘s nuclear program began with speed and impressive strategic effect on Friday. Still, the United States will face significant military and counterterrorism challenges as the conflict continues.

Israel’s early successes are significant. Numerous high-ranking Iranian nuclear scientists and military officials, including the heads of the Iranian military, the Islamic Revolutionary Guard Corps, and the Guard’s Quds Force foreign covert action unit, were killed. The death of the latter official, Esmail Qaani, is manifestly good news for the U.S. — Qaani plotted numerous assassination attempts against top U.S. officials, including President Donald Trump. Numerous Iranian nuclear facilities have also been struck, and further Israeli military action is expected over the weekend and into next week.

Recommended Stories

• The inevitability of MAID
• Perhaps there are drawbacks to sending ideologues abroad
• Good night, and good riddance

Similar to its 2024 action against the Lebanese Hezbollah, Israel has gutted Iran’s command and control apparatus and undermined its Supreme Leader Ali Khamenei’s center of gravity. Khamenei is now forced to choose between risking his fragile regime with escalation or yielding to Israeli power. Khamenei may choose limited retaliation of a kind designed only to save face. But, believing this is the greatest existential challenge to Iran’s Islamic Revolution since the 1980-1988 Iran-Iraq War, it is far more likely that he will choose persistent retaliation of a diverse and deadly kind. And if he does so, this conflict will carry significant challenges for the U.S.

For a start, Israeli Prime Minister Benjamin Netanyahu has clearly taken a bold gamble in breaking with Trump’s preferred diplomatic strategy toward Iran. I disagree with commentators who argue that Trump’s diplomacy up until now was only part of a masterful deception plan to lull Iran into a false sense of security. On the contrary, Trump’s instinct is to seek diplomatic resolutions wherever possible. While his diplomatic overtures to Iran were struggling and time was running short, a deal was still feasible. This matters because Trump and his MAGA base have strenuously made plain their disdain for new conflicts in the Middle East. And while Trump is still pushing Iran to rejoin diplomatic talks, the prospect of it accepting that invitation is now laughable.

Instead, the U.S. military is now preparing to engage in a multiday defensive air and naval effort to protect Israel and other U.S. allies in the region from Iranian retaliatory attacks. Unlike in previous situations, such as Iran’s October 2024 missile attack in which the U.K. military helped defend Israel, the U.S. defensive effort may be U.S.-IDF-only due to U.K. concerns about protecting Israel following an Israeli-instigated attack. If Iran attempts to reconstitute its nuclear program deep underground, Israel will engage in semipersistent strikes for the foreseeable future. These strikes will then likely precipitate continuing Iranian retaliation, requiring persistent U.S. military deployments to defend Israel.

In addition, if Iran now rushes to develop a nuclear weapon (estimated to take 2-6 months), the U.S. will likely be forced to directly participate in Israeli strikes against Iran’s nuclear program. The IDF lacks the force capacity to wage a high-intensity campaign against targets of opportunity in what would be a military campaign of strategic urgency.

The overarching challenge here is that defending Israel and other U.S. allies will require the expenditure of overstretched U.S. forces and finite air-defense munitions that will be in very short supply in a war with China over Taiwan. Seeing as China is expected by most U.S. military analysts to invade Taiwan between 2027-2030, and that a successful invasion would be catastrophic for U.S. strategic interests, this trade-off concern cannot be underestimated. Indeed, it underlines why messy diplomacy would be preferable to messy war.

This concern about munitions and force expenditure is especially pertinent to the U.S. Navy, which currently only has one carrier strike group in the Middle East. If, for example, the Iranian navy and Guard navy attempt to close the Strait of Hormuz or otherwise disrupt international maritime traffic, the U.S. Navy will have to engage in a sharp, intensive, and somewhat risky conflict.

Then there’s the counterterrorism concern.

While the Guard and its primary proxy, the Lebanese Hezbollah, have been heavily degraded by Israeli action, they retain a significant presence in Africa, Latin America (including relations with drug cartels that have significant logistics networks inside the U.S.), and Europe. They also retain a limited presence inside the U.S. Iran will likely now engage these elements to expand their current assassination plots against U.S. persons to include attack plots against U.S. civilians more generally. Expect the U.S. to expel some Iranian diplomats (terrorist-minded spies) from New York City in short order, for example.

WHAT HAPPENS WHEN THE JALISCO NEW GENERATION CARTEL KILLS AMERICANS

As evidenced by recently detected plots in the United Kingdom, Iran’s external terrorist portfolio remains diverse and capable. Iran’s terrorist threat will be sustainably significant on at least a short-medium term basis. A particular concern will be Jewish-American civilian targets, American tourists abroad, and airports and passenger aircraft that lack effective security protections. Put simply, anyone who says the Iranian terrorist machinery is already out of action is an idiot.

Yes, from Israel’s perspective, this conflict is necessary to prevent a second Holocaust and is highly positive in how it has fared so far. However, for the U.S., the experience will unlikely be limited to Trump’s statements and exciting television coverage.