When China was accused by the U.S. last summer of selling Iran Silkworm missiles that threatened shipping in the Persian Gulf, officials in Beijing entered the diplomatic equivalent of a consent decree. They denied having made such sales but promised to make none in the future. The same officials are saying even less about another recently disclosed missile deal: the sale to Saudi Arabia of an undisclosed number of intermediate-range CSS-2 missiles capable of reaching virtually anywhere in the Middle East, including Israel.
U.S. intelligence agencies confirmed the missile deal only about two months ago, and it was disclosed publicly in...