Pakistan and India have begun sharing intelligence on Islamic extremists, with the prodding of the US, in an arrangement that represents unprecedented cooperation between the two nuclear-armed South Asian nations. Washington hopes the cooperation will get a lift from last week's Indian elections, in which the incumbent Congress Party won by a wide margin over a Hindu nationalist party traditionally more hostile to Pakistan. With the Congress party's recent win in India's elections, intelligence reporter Siobhan Gorman explains why the time may be right for longtime rivals Pakistan and India to forge an alliance that allows for greater intelligence sharing with the U.S. The Central Intelligence Agency arranged for Pakistan and India to share information on Lashkar-e-Taiba, the group widely blamed for last November's terrorist attack on Mumbai, as well as on Taliban commanders who are leading the insurgency against Pakistan's government, said US officials. The US is stressing to Indian and Pakistani leaders that they face a common threat in Pakistan-based militant groups. Washington hopes that when India sees the intelligence and evidence that Islamabad is seriously fighting the militants in some areas, it will ease its deployments against Pakistan -- which in turn would prompt Islamabad to put even more focus on the battle at home. "We have to satisfy the Mumbai question, and show India that the threat is abating," said a US official involved in developing Washington's South Asia strategy. India and Pakistan traded military threats across their border in the wake of the Mumbai attacks, in which terrorists left more than 170 people dead. The CIA and US diplomats tried to ease the tension, urging Pakistan to crack down on the sources of the attack. Pakistan banned Lashkar and detained six people in connection with the attack, partially mollifying Indian outrage. Intelligence sharing on Mumbai has led to a somewhat more frequent exchange of information, U.S. and Pakistani officials said. India and Pakistan have shared "a lot" of information with each other about the Mumbai attack, said an official at Pakistan's Inter-Services Intelligence spy agency. He said the CIA was initially used as a conduit but the two countries now work directly with each other, while keeping the CIA in the loop. Trading Information India and Pakistan are sharing intelligence on Islamic militants, with US help. * India gets: Information on groups that threaten it, including the one that carried out the Mumbai attacks. * Pakistan gets: More trust from India that it is serious about taking on militants. * U.S. gets: Sharper Pakistani focus on the battle against the Taliban and al Qaeda. The official cautioned, "We're not going to tell them everything we know and they're not going to tell us everything they know. Nobody expects that to happen. ... But we're talking about [the attack]. We weren't doing that in December." A U.S. official said Washington isn't "under any illusions" about the difficulty of erasing decades-old suspicions between India and Pakistan, but sees some progress. U.S. officials hope that a calming of tensions can allow India's Congress Party government, strengthened by its election victory, to resume peace talks with Pakistan over the disputed Himalayan region of Kashmir. Some U.S. officials believe Lashkar-e-Taiba orchestrated the assault specifically to undermine the peace process. The Obama administration has been concerned that Lashkar could carry out a second strike on India in a bid to stoke a war. President Barack Obama came into office pledging to craft a regional solution to the instability in Afghanistan and Pakistan. The CIA and other intelligence agencies are stepping up efforts in the Pakistani tribal areas, tapping and tracking the location of the cellphones of Taliban commanders as well as taking pictures and collecting information in their training camps, according to a person familiar with the efforts. The U.S. shares this information with Pakistan, and sometimes with India, to reinforce the U.S. argument that the Taliban threat to Pakistan is greater than the Indian threat. Soldiers keep guard inside the UNHCR (United Nations High Commission for Refugees) Jalozai camp, where hundreds of families are seeking refuge from a military offensive in the Swat valley region, about 140 km (87 miles) north west of Pakistan's capital Islamabad May 20, 2009. The U.S. also sometimes brings intelligence on Pakistan's efforts to combat militants to India's attention, with Pakistan's consent, this person said. Examples include showing Indian officials evidence of progress against militants in the Pakistani regions of Bajaur, Swat, and Buner. U.S. intelligence officers have been able to track the whereabouts of key Pakistani Taliban leaders, such as Baitullah Mehsud, accused of orchestrating the murder of former Pakistani Prime Minister Benazir Bhutto, said this person. Sufi Muhammad and Maulana Qazi Fazlullah, leaders of a militant group aligned with Mr. Mehsud, are also tracked, according to the person familiar with the efforts. Mr. Muhammad brokered the now-defunct deal between the Pakistani government and the Taliban to enforce Islamic Sharia law in the Swat region in Pakistan. The government of Pakistani President Asif Ali Zardari is hoping that Congress's victory can also provide the Indian government with the political cover to move one or two divisions away from the Pakistan border in coming months, according to an official briefed on the diplomacy. But Indian officials say they aren't ready to do so. An Indian government official said New Delhi has documented an escalation of cross-border infiltrations by Pakistani militants into Kashmir.