with the world during the Khmer Rouge...
The U.S. supported the Khmer Rouge after
they were forced out of power by the Vietnamese. While the Khmer
Rouge retreated back to the Thai border, the U.S. encouraged China
to supply them with weapons so they can regenerate their army and
take back the country. U.S.'s reasoning for this support was that
the Khmer Rouge is Vietnam’s enemy, and Vietnam is the U.S.’s
enemy. The U.S. felt the enemy of their enemy was their friend;
therefore, it was okay to aid the Khmer Rouge. This resulted in
the U.S. embargo of the Vietnamese controlled Cambodia.
Source: Lairson, Thomas D. “Postwar
Vietnam 1975-1979 the choices of the Hanoi government.” Vietnam
an Interactive Tour.6 Oct. 2003.