The most obvious thing about Russian President Boris Yeltsin's sacking yesterday of his latest prime minister - the fourth one he has fired in 18 months - is that it is a sign of weakness, not strength. Well into his final year as boss in the Kremlin, Mr Yeltsin finds himself directing less and less outside its fortress walls. Rivals are manoeuvring to succeed him, forming alliances he cannot break, and his policies are applied erratically at best. As one more bit of the tribal Caucasus, this time Dagestan, threatens to break away, the impression grows that no one quite controls the largest leftover of the former Soviet empire. The dismissal of prime minister Sergei Stepashin and his entire cabinet came without warning, and Mr Yeltsin gave no reason. As Mr Stepashin said: 'He thanked me for good work - and fired me.' However, the causes probably include Mr Yeltsin's desire to survive his term by thwarting potential foes and being remembered for bringing democracy to Russia. The latter is an admirable goal. But his failing health and erratic style prevent him from accomplishing much more than befuddling his enemies while antagonising a disenchanted public. There are signs that economic gains are possible again after years of decline. But Russia remains a misruled nation. Corruption and cronyism permeate the government and social problems mount. Moscow needs dynamic leaders, but Mr Yeltsin has trouble visiting his office more than twice a week. Parliamentary elections on December 19 and a presidential vote in mid-2000 may give politics some needed energy. But naming yet another former spy as prime minister and his preferred successor won't build the trust and competence Russia needs.