The answer rests in Trump's head. Militarily, objectives are clear: decapitate regime, degrade military, destroy nuclear/missile capacity. Beyond that, it's unclear if it's regime change or just removing leadership. That determines duration.

Iran's major objective is survival. They are trying to draw others into the fight by attacking Gulf countries and using proxies to broaden the conflict and produce pain for the US.

The war is a race. The US/Israel are trying to degrade Iranian launch capacity while using interceptors. Which gets depleted first? It's like firing Ferraris at an e-bike—expensive interceptors vs. cheap Iranian weapons.

It informs his timeline, even if not stated publicly. He has to calculate whether to continue or find an off-ramp. He's hinted at options from continuing until new government to modest military objectives.

China has a huge stake in regional stability due to oil imports and navigation. They'd want de-escalation, but Trump is unpredictable.

China faces the problem of finding who's in charge in Iran, as decisions are delegated to field commanders not taking orders from Tehran.

They are likely urging de-escalation. They see value in degrading Iran's threat but depend on a conflict-free environment for economic growth.