ST. PAUL, Minn. -- Republican presidential nominee John McCain abruptly canceled a scheduled appearance on CNN's "Larry King Live" Tuesday in retaliation for an earlier interview on the network, in which an anchor raised questions about vice-presidential candidate Sarah Palin's foreign policy credentials.

In the interview, which aired Monday night, anchor Campbell Brown asked McCain spokesman Tucker Bounds repeatedly to cite "just one decision" Gov. Palin made as commander of the Alaska National Guard, a position Mr. Bounds...