In late 1967 and in early 1968, Sihanouk signaled that he would raise no objection to hot pursuit of communist forces by South Vietnamese or by United States troops into Cambodian territory. Washington, in the meantime, accepted the recommendation of the United States Military Assistance Command--Vietnam (MACV) and, beginning in March 1969, ordered a series of airstrikes (dubbed the Menu series) against Cambodian sanctuaries used by the North Vietnamese and the Viet Cong. Whether or not these bombing missions were authorized aroused considerable controversy, and assertions by the Nixon administration that Sihanouk had "allowed" or even "encouraged" them were disputed by critics such as British journalist William Shawcross. But in retrospect, Sihanouk allowing US bombing as a counter-weight to his previous decision to allow the Vietnamese to establish base areas seems consistent with his policy strategy in that US was the only force he could use as a counter-weight to the Vietnamese presence in Cambodia.