Pakistan said Dec. 13 that two Indian fighter aircraft violated its airspace. The Indian government has made no official statement, but the Indian air force is denying the incursion. Details are sketchy, but preliminary reports suggest the first incident occurred at 11 a.m. local time along the Line of Control in Kashmir, and a second incursion occurred at 12:20 p.m. local time near Pakistan's second-largest city, Lahore, near the international border in Pakistan proper. Pakistani authorities said that jets on patrol forced the Indian planes, which had penetrated some 2.5 miles into Pakistan, to retreat to the Indian side of the border. Pakistani Information Minister Sherry Rehman said officials had contacted the Indian air force, which said the violations were inadvertent. Given the tensions between the two nuclear neighbors after the Mumbai attack, and the details of the intrusions, it is unlikely that these incidents were accidental. Rather, New Delhi is increasing pressure on Islamabad to take concrete action against Islamist militants and their sympathizers within the Pakistani military-intelligence establishment. Pakistan has acted against assets and personnel of Jammat-ud-Dawah (JuD), the front organization of Lashkar-e-Taiba, the group India claims masterminded the Mumbai attack, which killed some 163 people and wounded hundreds of others. Earlier this week, the United Nations declared JuD and its principals terrorist entities, and afterward Islamabad banned the group. Also, STRATFOR sources have said that Pakistan, under pressure from both India and the United States, has removed several dozen operatives from Inter-Services Intelligence. However, Islamabad has refused to hand over any Pakistani nationals to India. Furthermore, India does not trust that Pakistan is willing and/or able to rein in militant Islamists. This is because Islamabad has arrested such actors and banned militant Islamist groups in the past, only to allow them return to business as usual. This situation, along with domestic pressure, is forcing the Indian government's hand and pushing it toward taking unilateral military action against Pakistani-based militants. That said, New Delhi is concerned that any conflict with Pakistan could worsen security for India and in the broader region. Trying to balance between the need to act and the need to exercise caution, New Delhi likely ordered the incursions as a means to sustain the pressure to shape Pakistani behavior. Although the official Pakistani response has been to downplay the incident, the incursions have triggered angry reactions from both civil and military authorities, including the Punjab and Pakistani-administered Kashmiri governments and the country's air force. Between the airstrikes carried out by U.S. drones on its western border and incursions by Indian aircraft on the eastern frontier, this is a nightmare scenario for Pakistan. Islamabad could afford to ignore U.S. action, but it cannot accept similar action from India. Pakistan will have to react to India, leading to a potential clash. Although this particular incident does not appear to have escalated, the potential for more aggressive Indian military action and the possibility of escalation on both sides remains very real.