ON JUNE 4th an unmanned CIA “drone” aircraft struck in Pakistan's remote tribal area of North Waziristan, apparently killing al-Qaeda's deputy leader, Abu Yahya al-Libi. The American administration, which had put a $1m price on his head, cheered the news. Mr Libi, a Libyan ideologue, had been on the run since 2005, thumbing his nose at the Americans since his escape from one of their jails in Afghanistan. In a bilious stream of videos and pronouncements, he preached the cause of global jihad.

Pakistan ought, by rights, to have cheered the news too. After all, Mr Libi had called upon Pakistani Muslims to rise up against the civilian and military establishment. Instead, Mr Libi's presumed death only deepened the rift between two supposed allies. Patriotic Pakistanis greatly resent the drone attacks over their territory. The country's armed forces felt humiliated by the secret American raid on Abbottabad a year ago that got Osama bin Laden. They were furious that 24 soldiers, manning a post on the border with Afghanistan, were killed last November by American aircraft in a ghastly “friendly fire” incident, and the government demanded an apology it has yet to receive. At a NATO summit in Chicago last month, President Barack Obama refused to meet his counterpart, Asif Ali Zardari, without Pakistan's agreement to reopen the southern route supplying the war in Afghanistan that Pakistan closed in a huff late last year.

The tempo of drone attacks against al-Qaeda figures had slackened in the weeks before the NATO summit, partly because of the Obama administration's desire to get a deal on the southern supply route. Since the Chicago flop, however, the attacks have gathered pace again.

American drones over Pakistan's tribal belt have wreaked havoc on al-Qaeda, killing over three dozen senior commanders. Following Mr Libi's presumed death, perhaps the only significant figure believed to be left there is Ayman al-Zawahiri, the group's leader since bin Laden's assassination. Mr Obama is said personally to oversee the “kill list”.

Although some officials on both sides want to end the alliance between Pakistan and the United States, the policy in both capitals is to remain engaged. Talks continue in Islamabad in the search for a way out of a diplomatic morass that, among other things, risks complicating the planned exit of front-line Western troops from Afghanistan by the end of 2014. The difficulty is that, with a parliamentary election likely in Pakistan not long before America's presidential election in November, domestic politics hems in both sides.

The bilateral talks are now chiefly over inducements to the Pakistanis to reopen the supply route. After the American-led invasion of Afghanistan in 2001, Pakistan gave free passage to supplies for the coalition soldiers. More recently, a token charge of $250 a lorry was imposed. Now Pakistan is demanding a transit tax of over $5,000 a lorry, which the American defence secretary, Leon Panetta, describes as “price gouging”. The Americans want to keep the price below $1,000 a lorry, whereas the Pakistanis might settle for double that.