Why did America leak a report on Hizbollah chief killing?

A detailed report in the Washington Post last weekend revealed that, contrary to popular belief in the Middle East, the 2008 assassination of Hizbollah operations chief Imad Mughniyeh was largely carried out by the CIA, rather than Mossad.

According to the report, the information on Mughniyeh's location in Damascus came from the Israeli intelligence, but the decision to kill him and the bomb used, hidden in the spare tyre of an SUV, had been manufactured by the CIA and smuggled into Syria by its operatives. Mossad officers were responsible for identifying the target and triggering the device.

While neither Israel nor the US have officially acknowledged their involvement, former CIA officers and administration officials confirmed that President George W Bush had personally sanctioned the operation.

Mughniyeh was believed to have been involved in a string of terror attacks including the 1983 bombing of the US embassy in Beirut, where 63 people, including eight CIA officers, were killed. He was also thought to have helped organise the bombings of the Israeli embassy in Buenos Aires in 1992, and the attack on the Jewish Amia centre in the same city in 1994.

In Israel, there has been feverish speculation over the timing of the Washington Post report.

One theory is that the Obama administration wanted to use the leak to emphasise the security alliance between the two countries at a time when the Netanyahu government is challenging the US over its prospective deal with Iran.

Some linked the leak to Prime Minister Benjamin Netanyahu's scheduled speech to Congress next week, which has infuriated the administration.

Another theory is that Israeli and US groups facilitated the leak in order to sabotage the talks with Iran. Mughniyeh was regarded by Iran's Revolutionary Guards as one of their own. The IRGC are opposed to a deal with the US and the revelation that it was the Americans who killed Mughniyeh will give them additional motivation to act against their rival, President Hasan Rouhani, who is interested in reaching a deal.