Yuri Skokov rarely makes public statements. He shuns media attention. Throughout the lifetime of the Congress of People's Deputies, the former Soviet parliament to which he was elected in 1989, he made not a single speech. When the Communist old guard launched its abortive coup in August 1991, his office in the Russian parliament building was empty, and no one knew where he was.
Recently, the Moscow magazine Novoye Vremya applied to interview him. His staff not only denied the request but refused even to release his curriculum vitae.
Yet Mr Skokov wields real clout - more than the liberal Prime Minister, Yegor Gaidar, more than the chairman of parliament, Ruslan Khasbulatov, and more than Mr Yeltsin's Vice-President, Alexander Rutskoi. That is because he is the secretary of Russia's Security Council, an unelected and secretive body which, since its powers were greatly expanded by a presidential decree last July, has shown every sign of becoming the country's most important authority.
The Council appears to be answerable neither to parliament nor to the government. Though it is under Mr Yeltsin's nominal control, the man who runs its day- to-day business is Mr Skokov. He has the personal authority to ensure that all government ministries obey its decrees. He has also set up Security Council branches across Russia that supervise local affairs with the help of the interior and security ministries.
Last Thursday Mr Skokov increased his power. He was named as the secretary of a new council of the leaders of the Russian Federation's republics - places such as Tatarstan, Bashkortostan and Yakutia that are striving for autonomy from Moscow. Moreover, Mr Skokov's Security Council will supply the staff for this body.
'Skokov, having received carte blanche from Russia's republican leaders, is extending the Security Council's influence, and his own, to the entire Russian Federation,' the liberal newspaper Nezavisimaya Gazeta commented. 'At last Moscow will have the chance to exercise rigid control over the ethnic situation in the republics.'
Mr Skokov was born in Vladivostok in 1938 and, after graduating as a radio engineer, worked for almost 30 years in Soviet military research. In 1990, he became a deputy prime minister in one of the last Soviet governments. After last year's failed putsch, Mr Yeltsin asked him to set up the Security Council.
Since then, while the West's attention has centred on the energetic young economic reformers in the Russian government, Mr Skokov has quietly used the Council to acquire ever greater powers. He has also held responsibility for military personnel policy - a role that may explain the recent appointment of several noted conservatives to senior military posts.
Novoye Vremya's profile described Mr Skokov as 'a military- industrial general director to the marrow of his bones . . . The free- market system is absolutely alien and inconvenient to him. He does not understand how economic relationships can be based on personal interest. He is a distinct authoritarian. The only method he uses is to rule by decree.'
Significantly, the far-right Russian press, which detests the reformers in Mr Yeltsin's entourage, has refrained from criticising Mr Skokov. Still, the two men appear to get on together. It seems that Mr Yeltsin, like Mikhail Gorbachev before him, believes he can play off left against right. Mr Gorbachev's fate is, of course, well-known.