Washington's decision to withdraw diplomatic recognition from the Cambodian coalition dominated by the Khmer Rouge was announced, tellingly, by Secretary of State James A. Baker 3d after a meeting with his Soviet counterpart, Eduard A. Shevardnadze, in Paris on Wednesday.

Instead, the United States should encourage a new Cambodian coalition that excludes the Khmer Rouge by working with Vietnam to foster power sharing, and also condition further aid to the non-Communists on splitting from the Khmer Rouge.

They have promised to withdraw the rest of their troops by the end of September but want to insure that foreign aid to the Cambodian coalition fighting Phnom Penh will stop simultaneously.

Vice President Dan Quayle met here today with Prince Norodom Sihanouk, the leader of the Cambodian coalition opposed to the Vietnamese-backed Government in Phnom Penh, to show American support for the Prince before his negotiations with the Cambodian Prime Minister.

There is no precedent for enforcing the convention, but the commission believes the case would bring diplomatic pressure on the Cambodian coalition to "get those most responsible for genocide out of their current positions, and out of the jurisdiction of democratic Kampuchea," Mr. Hawk said.

A4 In Indonesia, Vice President Quayle met Prince Norodom Sihanouk, the leader of the Cambodian coalition opposed to the Vietnamese-backed Government in Phnom Penh, to show American support.

The commitment he attributed to the Chinese came a day before Secretary of State James A. Baker 3d announced in Paris that the United States was withdrawing its support from the Chinese-backed Cambodian coalition that includes the Khmer Rouge.

Following a recent British television documentary on Cambodia, members of Parliament were inundated with letters protesting British support for a Cambodian coalition that includes the Khmer Rouge as its most powerful component.

In another speech today, a member of the Cambodian coalition opposed to the Soviet-backed Vietnamese occupation of Cambodia accused Hanoi of using "genocide" and brainwashing to eliminate Cambodia's culture and absorb the nation into a Vietnamese-led federation.

Prince Norodom Sihanouk has decided to resume his post as president of the Cambodian coalition fighting the Vietnamese occupation forces, Thailand's Foreign Minister said today.