Cairo — Against the backdrop of US troop withdrawal and continued factional violence in Lebanon, two key Arab leaders brought strong messages to President Reagan this week.
Egyptian President Hosni Mubarak and Jordan's King Hussein want two things from the United States:
* More financial aid - especially military - to offset the growing power of aggressive Mideast states.
* A more active US effort to help settle the region's underlying causes of discontent - mainly the Palestinian question.
Their requests are highlighted by Mr. Hussein's meeting with Mr. Mubarak on Sunday in Washington, a step that helps bring Egypt back into the Islamic fold.
Egyptian officials - and other moderate Arab leaders in Jordan and Saudi Arabia - were not happy with the introduction of US Marines into Lebanon. But they believe the announced redeployment offshore could make the situation worse.
''The withdrawal of the Marines will give the Syrians more room and the Soviets after them,'' said Egyptian Prime Minister Ahmed Fuad Mohieddin in an interview with Western journalists here.
In the balance of Middle East power, both Jordan and Egypt are feeling particularly threatened. Jordan looks north to Syria, which now has the largest and best-equipped military in its history and has been responsible for terror attacks against Jordan, according to Jordanian and Western officials.
Egypt is also ''very much worried'' about the Syrian military buildup, according to Defense Minister Muhammad Abdul-Halim Abu Ghazala, and even more concerned about its neighbor to the west, Libya. While Libya and Syria continue to build their Soviet-stocked and Soviet-advised armed forces, Egypt is building its defenses at a much reduced level since it rejected Soviet assistance after the 1973 war with Israel and turned to the US for help.
Egypt is already in debt to the US for $5 billion in previous military loans. Debt service is costing Egypt $300 million a year and is expected to rise to $ 500 million by next year. President Mubarak is seeking a restructuring of this debt at lower interest rates, according to Egyptian officials. Even better, in Egypt's view, would be the foregiveness of some previous military loans or perhaps the shifting of some loans to grants, as the US has already done for Israel.
Jordan, which received the relatively small sum of $95 million from the US last year, would like the $200 million in new military aid sought from Congress by the Reagan administration. Officials in Amman envision a day when Jordan - provided it pursues peace with Israel and receives less help from oil-producing states - will need even more economic assistance from Washington.
Egypt does not enjoy the preeminence it once did in the Arab world, although it is reemerging from its exile by other Arab states following the peace treaty with Israel in 1979.
Although officials here vow they will never break their peace treaty with Israel, they describe it as a ''cold peace.'' Egypt's ambassador to Israel has not returned since his recall following the Israeli invasion of Lebanon in 1982. President Mubarak has publicly embraced Palestinian leader Yasser Arafat, and Egypt continues to push its plan of Palestinian self-determination along with mutual recognition of Israel and the PLO.
Both Jordan and Egypt would like more encouragement from Washington for their efforts to woo Arafat to a moderate position that would make way for the possible representation of Palestinians by King Hussein.
Officials in Amman and Cairo in recent interviews expressed great frustration and some bewilderment over continued strong US support for Israel, including last year's ''strategic cooperation agreement,'' following the invasion of Lebanon and the steady increase of Israeli settlements on the West Bank of the Jordan River.
''If Israel annexes the West Bank, the whole peace process will collapse,'' warned Butros Butros Ghali, Egypt's minister of state for foreign affairs.
Others here are more direct in their criticism of the US and what they see as its failure to moderate ''Zionism based on expansionism.''
''Who pays for Israeli policy? Who pays for the settlements?'' asks Ali Dessouki, professor of political science at Cairo University. ''As long as the United States continues its present policies, the fading away of the comprehensive Middle East peace process will continue.''
Moderate Arab leaders like Mubarak and Hussein say that Lebanon has distracted American public and political attention from the broader Palestinian and Arab-Israeli issues. In their meetings with President Reagan, they hope to draw attention to these issues and in so doing, show that the more reasonable Arab voices in the region ought to be more obviously and substantively nurtured.
''There is a fight in the Arab world between moderates and extremists,'' says Dr. Butros Ghali. ''This is the real confrontation.'