As Israeli officials lash out against a preliminary deal to end the war in Iran, President Donald Trump is returning the favor. "I'm not happy with the way Israel has handled themselves with Lebanon," Trump said Tuesday. "Israel would have been blown up a long time ago had I not gotten involved."

The comments represent a nadir in U.S.-Israel relations under Trump. The dispute is fundamental. Trump is determined to end the war with Iran, and Iran has made clear that a peace deal is only possible if Israel halts its operations against Hezbollah, an Iranian ally, in Lebanon. A purported leak of this week's memorandum of understanding between the U.S. and Iran explicitly states that the war in Lebanon must end as part of a broader deal.

Israel, for its part, believes its interests are best served by continued war with both Hezbollah and Iran, and it's insisting that it won't be bound by the terms of any deal negotiated between Tehran and Washington alone.

The only way to reconcile these positions is for one of the three countries to swallow a seemingly unpalatable compromise. In other words, if the U.S. wants to get its way, then it'll have to do something it has long avoided: force Israel to back down using America's extraordinary leverage over the country, including the roughly $4 billion in military aid the U.S. gives Israel each year.

At this stage, there is little indication that Trump is willing to take this step. But, given the rapidly increasing public support for ending weapons shipments to Israel, it's worth asking the question: what would happen if the U.S. cut off all military support for Israel?

Let's start with Lebanon. Military experts say a U.S. aid cutoff would slow but not end Israeli operations in the country. The most immediate impact would be to Israel's fighter jet fleet, which relies on U.S. weapons companies for maintenance.

Israeli F-35s, for example, "would probably not be able to operate for more than a month or at most two months without spare parts," said Josh Paul, who served for more than a decade in the State Department bureau that oversees U.S. weapons transfers.

Israel's stockpiles of air-to-ground missiles and air-defense munitions would allow it to continue its campaign in the short to medium term. But, given how many of those weapons are produced in the U.S., Israel would soon have to make difficult choices about where to focus its military efforts. Pro-Israel analysts are acutely aware of this fact; as two writers at the Foundation for Defense of Democracies wrote in 2024, Israel needs to build up its own military industry if it wants to "fight enduring battles on multiple fronts."