IF confirmed as United Nations secretary-general by the General Assembly as expected, Boutros Boutros Ghali will take on the world's top diplomatic job at a particularly critical moment in UN history.The demands on the position have been escalating at a time when the UN bureaucracy is increasingly unwieldy. Current Secretary-General Javier Perez de Cuellar, whose second term ends Dec. 31, has been trying to resolve everything from the civil war in El Salvador to the hostage crisis in Lebanon. He has staff help but he is the man at the center. Dozens of assistants report directly to him. Many UN experts say the situation must change. They hope that Dr. Boutros Ghali, known as a well-organized administrator during his many years in Egypt's Ministry of Foreign Affairs, will take up the challenge. "Getting the UN bureaucratic structure in order is in some ways the No. 1 priority," says Thomas Franck, a professor of law at New York University. "The key test is whether [Boutros Ghali] can delegate authority effectively ... so he can be relatively free to pursue his peacemaking and peacekeeping tasks.... He has the opportunity to make the organization into a realization of the dream it was [at its founding] in San Francisco." Some 22 UN member nations led by Australian Ambassador Peter Wilenski have developed a plan to streamline UN operations. The blueprint would increase the power of the secretary-general and make his office more effective. "Everything depends on the new secretary-general and whether or not he's keen to reform the UN administration - if he is, the reports are ready and waiting for him," says Tony Miller, press secretary to Australia's UN mission. "I should think he'd be interested in administrative reform just from the standpoint of self preservation," says Sir Brian Urquhart, a Ford Foundation scholar who worked under all five secretaries-general in a long career at the UN. He says the UN's top post is "an incredibly punishing job - because it just never stops." Boutros Ghali, who lobbied hard for the position before winning unanimous Security Council approval last week, is something of a man for all seasons. He has something in his background to offer almost every political group. He is an experienced diplomat who has a doctorate in international law from the Sorbonne and speaks fluent French (one of France's top criteria). The grandson of a former Egyptian prime minister, he is a Christian married to a Jew. He is both an Arab and an African. After three Europeans, one Asian, and one Latin American in the UN's top job, Africans, who account for one-third of the UN's membership, had argued it was their continent's turn for the post. Boutros Ghali was one of six candidates nominated by the Organization for African Unity. The other leading contender right up to the end was Bernard Chidzero, Zimbabwe's Finance Minister. In a straw poll of the Security Council's 15 members taken a few weeks ago, Boutros Ghali and Mr. Chidzero appeared to have about the same level of support. Some who have worked closely with the Egyptian diplomat over the years say he is a calm, persuasive, and effective leader. He accompanied the late Egyptian President Anwar Sadat to Israel and helped negotiate the 1978 Camp David accords. He is seen as a firm supporter of Arab-Israeli peace efforts but one who is not afraid to tell Israel when he disagrees with one of its policies. His ties with nonaligned and developing nations are particularly strong. "He always felt that it was important to maintain Egypt's role both in Africa and in the Arab world ... yet he has one foot very firmly planted in the West," says Alfred Atherton Jr., US ambassador to Egypt from 1979 to 1983. "He will be scrupulously fair. I think he's a first rate choice." "He's the ideal candidate - an absolutely superb choice," agrees Hermann Eilts, chairman of Boston University's Center for International Relations and another former US ambassador to Egypt, who says he has known Boutros Ghali for 20 years. The only publicly stated objection to Boutros Ghali's candidacy by US officials, who are otherwise openly grateful to Egypt for its role in forming the Arab coalition against Iraq during the Gulf war and for its peacemaking efforts with Israel, concerned age. He is 69 (the UN's official retirement age is 60) and says he would stay for one five-year term. The US wanted someone who would stay two terms. Mr. Atherton says he thinks the US concern makes little sense at a time when many people enjoy productive careers well into their 70s. "I haven't seen any dimunition of his energy level," he says of Boutros Ghali.