Perhaps no international border is as fraught with as much ongoing conflict as the one separating India and Pakistan. Even the demilitarized zone separating the Koreas, often cited as the archetypical example of cross-border acrimony, has been essentially static for over sixty years. During a comparable period of time, tensions along the border between India and Pakistan have erupted into full-scale war on four separate occasions, in 1947, 1965, 1971, and 1999. In late 2001 and early 2002, India and Pakistan were at the threshold of what would have been their fifth war in fifty-four years. The standoff was the result of a long-running territorial dispute that dates back to the partition of British India. Although the standoff ended without escalating into all-out war, it was the most serious of the India/Pakistan disputes that have taken place since the widespread availability of satellite imagery, and the preparations of both militaries went all the way to the brink. For these reasons, the events of 2001-2002 have much to teach us about the nature of conflict in this volatile region. This work formed part of a project on studying border conflict made possible by a grant from the United States Institute of Peace. Read more at www.aaas.org/geotech/borders.