Pakistan is under US pressure to clear the militant hub of North Waziristan on the Afghan border, a bastion of Afghan Taliban factions where allied Pakistani militants, Al-Qaeda and other foreigners also operate. The attempted car-bombing in New York's Times Square on May 1 has refocused international attention on the ethnic Pastun tribal region of rugged mountains, ravines and forests, which no government has ever fully controlled. Lieutenant General Sardar Mahmood Ali Khan, deputy chairman of the Joint Chiefs of Staff, told Reuters in an interview last Monday his forces would take action in North Waziristan but in their own time and when adequate resources were available. Here are some scenarios for how events could unfold: A limited campaign This is most likely. Pakistan already has a sizeable troop presence in North Waziristan, most in heavily fortified positions in the main town of Miranshah, from where they occasionally strike out at specific targets. This allows the military to focus its fire on its most dangerous enemies among the various factions there. This would satisfy the United States to an extent and when US pressure builds, the Pakistani army could intensify its operations. This strategy would appear to afford the Pakistani army a degree of control. The army can tailor its operations and respond to events as they unfold both at home and in Afghanistan. The Afghan factions could perhaps be pressed to enter talks in Afghanistan or even to hand over or isolate Pakistani Taliban or foreign fighters. Security force and civilian casualties could also be limited. Pakistan launches a full-scale offensive This is not likely although this is what the United States and Afghanistan would like to see. The Pakistani military has said there will be no “steam-roller” operation in North Waziristan, as there have been in places such as Swat, northwest of Islamabad, and South Waziristan. The army, which maintains a huge presence on Pakistan's eastern border with old rival India, says it is consolidating gains made in places such as South Waziristan, Bajaur and Swat, where there have been signs the militants are trying to stage a comeback, and its resources are limited. A full-scale offensive would also mean taking on the Afghan Taliban factions which have not been attacking the Pakistani state. Pakistan's fundamental security concern is the perceived danger from India and analysts say Pakistan sees the Afghan Taliban factions as tools for its long-term objectives in Afghanistan, where it wants Indian influence kept to a minimum and a friendly Kabul government. Pakistan also believes that with US forces due to begin withdrawing from Afghanistan next year, the Americans will soon be out, perhaps after some sort of a negotiated deal with the Taliban. So Pakistan would be loathe to make enemies now of the only Afghan factions over which it has influence. A full-scale offensive also carries risk for the government of a country where anti-US sentiment runs high. Heavy military and/or civilian casualties in fighting against factions not attacking Pakistan would bolster those who already say Pakistan is a US puppet fighting a US war. Morale in the armed forces could be undermined while militants would scatter across the northwest and into Afghanistan. Some could slip back to their homes, including the heartland province of Punjab, where they would launch bomb attacks. Pakistan does nothing This is also not likely. Many Pakistani Taliban fighters waging war against the state have fled from army offensives in South Waziristan and elsewhere in the northwest to North Waziristan from where they plot bomb attacks on the security forces and government and foreign targets across the country. The army and the civilian government know that eliminating those militants is key to ending the violence. Doing nothing would also infuriate the United States and strain Pakistan's relationship with its biggest aid donor. The United States, struggling in Afghanistan, would step up its attacks by pilotless drones and could even send in ground troops. That would enrage Pakistan and could lead to a breakdown of relations between the allies. Pakistan could throw the US operation in Afghanistan into question by shutting down supply routes running through Pakistan along which passes a large volume of US military supplies, from drinking water to fuel.