Glenn Reynolds notes that Unfit for Command author and John Kerry foil John O'Neill may have been in Cambodia during 1970 - but it was during the time of the well-known, publicly declared Cambodian incursion.

But, he asked: "By the way, has anyone looked to see if President Nixon (who of course wasn't President until January 20, 1969) ever denied that we had U.S. forces in Cambodia during the time that Kerry was serving in Vietnam?"

Answer: Yes.

According to transcript of Nixon's speech announcing the Cambodian incursion, Nixon said:

For 5 years, neither the United States nor South Vietnam has moved against these enemy sanctuaries because we did not wish to violate the territory of a neutral nation. Even after the Vietnamese Communists began to expand these sanctuaries 4 weeks ago, we counseled patience to our South Vietnamese allies and imposed restraints on our own commanders.

Of course, Kerry's side of the story - it appears - is that his trip(s) into Cambodia were unsanctioned, "secret" efforts in violation of U.S. policy. That may raise a list of additional questions. But the answer is, yes, Nixon denied U.S. incursions into Cambodia during Kerry's tour of duty in the region.

MORE: Not only did Nixon issue a blanket denial that the U.S. did not move against Cambodian territory before 1970, he even seemed to lament that there was no earlier action in an address to the nation a few weeks later:

This reality was brought home directly to me a few days ago. I was talking with a union leader from New York. His son died in Vietnam this past February. He told me that had we moved earlier in Cambodia, we might have captured the enemy weapon that killed his son.