American and Saudi Arabian credibility will be damaged among friendly Arab states if the Reagan administration's effort to sell airborne warning and control system (AWACS) planes to Saudi Arabia is blocked by Congress, Crown Prince Hassan of Jordan believes.

Such a defeat for Reagan and by extension for the Saudi royal family "would have an immediate impact in the region at a time of increasing polarization" between the United States and the Soviet Union, King Hussein's younger brother said in an interview Friday with Washington Post editors, "because it is definitely a test in terms of global security" and America's ability to "take steps to carry out its declarations of intentions on global security."

Hassan, visiting Washington before traveling to New York to address the U.N. General Assembly, also denounced reported Israeli intentions to withdraw the military government in the occupied West Bank and Gaza Strip territories and replace it with civilian authority, noting that the Israeli officials who would continue to be in control of the West Bank would be senior military men "who would put on civilian clothes, but not become a civilian government."

His remarks contained echoes of criticisms of the Reagan administration's stress on a strategic military U.S. presence in the Middle East rather than on a peacemaking role that were made in an interview earlier in the week in Amman by Hussein, who visits Washington in early November. The pronouncements and the scheduling of Hussein's visit appear to herald a return to a highly active role in Middle East affairs by Jordan, which has sat on the sidelines since the Camp David agreements in 1978 provoked a sharp rift between Amman and Washington.

The absence of a high-level U.S. diplomatic envoy such as the Carter administration named to watch over Middle East peace efforts is undermining American involvement in the region, Hassan argued, saying that the United States should provide "an impartial third voice" in the continuing Egyptian-Israeli negotiations on the Palestinian problem. He suggested widening the role of Philip Habib, the veteran diplomat used by Reagan to defuse the confrontation that developed around the stationing of Syrian surface-to-air missiles in Lebanon earlier this year.

The remarks by the prince, who has concentrated on national and regional economic development in recent years, also suggested that Jordan is turning more attention to its potential role as an intermediary between the West and the Persian Gulf oil-producing region as the impasse on the West Bank continues and, in his view, grows worse, with U. S. military aid helping "Israel come into its own as a power that can reshape the map in the area."

Jordan has fashioned working alliances with Saudi Arabia and with Iraq, the largest Arab oil producers in the area, and provides a large number of the technical experts working in Persian Gulf economies and military establishments.

Asked about the continuing emphasis that Israeli Defense Minister Ariel Sharon and Foreign Minister Yitzhak Shamir place on the East Bank of Jordan as an already existing "Palestinian homeland" that should be given to the Palestinians even if the Hashemite monarchy is overthrown in the process, Hassan described such suggestions as "an extremely irresponsible attempt by Israeli military planners to try to get pseudo-radical regimes on their border that they can then deal with by military means and belligerence. It is not a question of alternative homelands, but of alternative leaderships, and Israel has to decide whether it wants to live with stable or pseudo-radical neighbors."

Referring to the large number of West Bank Palestinians who are leaving the area Israel captured from Jordan in 1967 and going to the oil countries of the region, Hassan charged that "Israel is hot-housing the radicalism that it says it fears, and exporting it to the area of greatest Western concern, the gulf."