The scare over Aliyev, 75, was a reminder that Boris Yeltsin is only one of many aging leaders in the volatile states of the former Soviet Union. Diplomats in Moscow are on round-the-clock watch for health and assassination threats against the lives of Yeltsin, Aliyev and his fellow septuagenarian, Georgian leader Eduard Shevardnadze. In the politics of personality that passes for ““emerging democracy’’ in the Caspian region, none of these leaders has prepared for his own departure. Apparently, diplomats say, they expect to rule for life. The worry in the West focuses on Azerbaijan because of Aliyev’s role in holding off Russian ambitions to regain control over Caspian oil. ““The political system Aliyev has constructed is based on him and his living presence,’’ warns a U.S. government expert on the region, adding that when Aliyev leaves, the likelihood of a bitter power struggle ““could give Moscow a chance to try to install its own puppet.''

Western nations have encouraged the Caspian strongmen to ease their grip. But in the last four months, both Aliyev and Kazakhstan President Nursultan Nazarbayev, a comparatively youthful 58, have shrugged off U.S. and European criticism of their suspiciously overwhelming election victories. Even the Caspian leader most familiar with the West, Shevardnadze, seems dimly attuned to its concerns over succession as presidential elections approach next year. ““Usually all the foreign investors ask for some guarantees,’’ says Peter Mamradze, the Georgian leader’s chief of staff. ““And to reassure them, Shevardnadze says, “I am here and shall remain here’.’’ As for mortality, a joke now popular in Baku has Aliyev asking his granddaughter what she wants to be when she grows up. ““President,’’ she says. Puzzled, Aliyev replies, ““Why do we need two presidents?''

Aliyev learned to assume leadership in the Kremlin, where he was a Politburo boss before returning home. He became president in 1993. Four governments had fallen in two years, and Aliyev himself would survive at least two coup attempts and a war with Armenia that cost Azerbaijan a fifth of its territory. Eventually, Aliyev managed to pacify his own republic and, working with the Clinton White House, to sign 13 contracts worth a total of $30 billion with foreign oil companies–the most recent with a Japanese consortium in December. Aliyev may be planning to pass the mantle to his son, Ilham, a state oil-company executive, but most diplomats doubt Ilham could weather inevitable challenges from regional clans, mafia leaders and exiled politicians. ““The stability of the country depends on [the elder Aliyev],’’ says a U.S. oil executive. ““He is known as among the most skillful manipulators of both the Soviet and post-Soviet systems.’’ But even he can’t manipulate mortality forever.