THE LATEST shootings on the India-Pakistan border signify big trouble. They suggest that last month's cooling of war threats exchanged by the two countries is transient and unstable. Worse, they suggest that the two consider the threat of another, fourth war -- which in their new circumstances could well be nuclear -- a plausible line of policy. India and Pakistan are carelessly and arrogantly ignoring their responsibility to step back from the nuclear brink.

The new Indian-Pakistani aerial bumps on the border, not to speak of the continuing violence in Indian-held Kashmir and the near-permanent fighting on a high Himalayan glacier, are all part of a confrontation that issued from the birth of India and Pakistan as post-colonial states some 50 years ago. Those bumps have little to do with security. The two governments use their border tension as a kind of political theater with which to distract their publics from their deeper obligations to peace and development. That both governments have prideful and professionally able militaries sharpens their sense that they can keep things under control. To be perceived at home as ready and willing to court risks abroad seems to guide policy on both sides.

Here is where the danger lies. India and Pakistan are in the grip -- the loose grip -- of politicians who seem unable to grasp their duty to their electorates and, as well, to the foreign populations that would suffer from the overflow of a nuclear exchange. For instance, neither country chooses to pay serious heed to the agreement they concluded in 1991 commiting them to avoid border air space violations. India and Pakistan are distinctive, a new Stimson Center report notes with apprehension, in failing to employ such diplomatic devices to verify military border agreements, provide transparency, ease rising tensions and generally build confidence.

Possible dangers to the international peace of far less consequence than this one are routinely accorded far greater international attention. This one can no longer be counted on to work itself out. India and Pakistan cannot be forced to be responsible. But they can be called on in all available forums to answer why they are sliding toward nuclear war.