New Delhi, March 2 -- The US and Israel are betting on regime change in Iran through air attacks that began on Saturday. So far, bombardment has left Iran's top leader Ayatollah Khamenei dead and sparked a retaliatory flare-up in West Asia.

This is a gamble, although US air-strike precision has improved since its 2003 war on Iraq to end Saddam Hussein's rule, an invasion that left countless civilians dead and inflamed the region.

This time, the White House has urged Iranians to rise up and overthrow their rulers. It expects a youth rebellion to depose a "threat" that has long defied its authority. Will the US invade to see that aim met?

In a best-case scenario, it won't-and an oil-price spike would be brief. However, a tail-risk case o...