WASHINGTON  Videotape of the Navy mission to shoot down a dying spy satellite made available Thursday shows an interceptor missile ascending atop a bright trail of burning fuel, and then a flash, a fireball, a plume of vapor. A cloud of debris left little doubt that the missile had squarely hit its mark as the satellite spent its final days orbiting more than 130 miles above the Pacific Ocean.

A different kind of doubt still lingers, though, expressed by policy analysts, some politicians and scientists, and not a few foreign powers, especially China and Russia:

Should the people of the world be breathing a sigh of relief that the risk of a half-ton of frozen, toxic rocket fuel landing who knows where has passed? Or should they be worried about the latest display of the United States’ technical prowess, and see it as a thinly veiled test for a shadow antisatellite program?

Defense Secretary Robert M. Gates, who personally gave the order to go ahead with the satellite shootdown Wednesday, told reporters in Hawaii on Thursday that he was prepared to share some details of the operation with China to ease its concerns that the debris might still prove dangerous. Adm. Timothy J. Keating, the commander of American forces in the Pacific, has reached out to several nations in the region to explain the mission, as well.

Addressing the diplomatic concerns, senior officials dismissed questions raised by the Chinese and the Russians, and echoed by some arms control analysts, about whether the episode was really a test of space weaponry. They pointed out that the missile used in the operation, the Navy’s SM-3 interceptor, was designed to counter a limited ballistic missile attack and had to be reprogrammed for this unexpected task, the likes of which the authorities are unlikely ever to face again.