Mikhail Gorbachev commands an extraordinary bundle of assets as he embarks upon his duties as Russia's foremost political leader.

He has time enough to consolidate power and then address Russia's long-term economic problems. He has a personality that lends itself to television as a means of engaging popular support at home. In foreign policy he has many cards to play, including a Big Two summit and a position of real strength against China.

At 54, Gorbachev can look forward to a good 15 years as general secretary. He has been working as No. 2 man in the fastness of Communist Party power, the Secretariat, for at least a year. So the party machinery is already in his hands.

The KGB, or secret police, once the fief of Gorbachev's great patron, Yuri Andropov, has been openly backing him in recent months. The army may be a problem, since it supposedly has ties to one Politburo rival, Grigori Romanov, the former Leningrad boss. But the shuffling off of the former chief of staff, Nikolai Ogarkov, suggests that Gorbachev has already lined up military support. The combination of backing from younger party people, the KGB and the army has led some Kremlinologists to consider Gorbachev the candidate of the "let's get Russia moving again" party.

The old guard of the party, led by Prime Minister Nikolai Tikhonov and Foreign Minister Andrei Gromyko, undoubtedly constitutes a powerful dead weight against change. Of course Gorbachev can simply outwait them. But if, as seems more likely, he moves aggressively to take charge, he has ample occasion. A new Party Congress and a new Five Year Plan are both in the works.

Moreover, he can wield against the old guard a weapon he began to use in the last days of the Chernenko era. One sure sign that the passage of power was at hand came from the television appearances both men made in casting ballots for election to Russia's rubber-stamp parliament, the Supreme Soviet. In contrast with the dying Chernenko, Gorbachev presented a picture of good health and competence. He played with his grandson and joshed with reporters. It will be surprising if Gorbachev doesn't turn television to advantage again. It is even possible that after years of indifference Russians will come to feel a bond with their leader.

If so, a start will have been made on addressing the economic problem. For it is not as though Russia lacks resources or an increasingly well-trained population. On the contrary, there has been a steady -- if slow -- improvement in living standards. Indeed, grain is in short supply precisely because meat has come to bulk large in the diet.

The problem has been lack of incentive and motivation. Drunkenness has actually brought a drop in life expectancy among males, and absenteeism is chronic. So reform could yield big dividends, and a general secretary in harmony with opinion would have an advantage in breaking the grip of a privileged bureaucracy on the Soviet economy.

While economic reform remains a great unknown, and will plainly take years, foreign policy gains can come more quickly. Russia enjoys a decided edge over the other communist giant, China. In effect, the Chinese have ceased to challenge Russia's military buildup and the policy of encirclement that runs from North Asia through Afghanistan to Vietnam. Easing the military pressure by some token withdrawals would cost Russia nothing. It would break up the Sino-American tie -- which is increasingly a defense relation. It would ensure Russia's place in the Pacific.

A similar suppleness would pay in dealing with Eastern Europe. The East Europeans want to thicken economic and cultural ties with Western Europe. In so doing they would take some of the strain off the Soviet economy. But such ties pose no threat to Soviet security. For Russia is overwhelmingly the foremost military power on the Continent. Moreover, the East European leaders, whatever their interest in improving living standards and stressing national themes, would all be out of office if they really broke with Moscow.

The West Europeans and Japanese want keenly to trade with Russia and Eastern Europe. They are eager to supply much of the technical equipment Moscow needs so badly. They are even prepared to make loans on concessionary terms. Hence Margaret Thatcher's comment, when Gorbachev showed a human face in London, that "We can do business."

Nor can the United States easily resist a Soviet leader with a touch of charm. Soviet ham-handedness in such matters as the downed Korean airliner and the poor health of the last three Russian leaders made it easy for President Reagan to turn away from serious negotiations. But Gorbachev can play the summit card. Reagan, aware of that possibility, has already issued -- without preconditions -- an invitation to a meeting.

Up to now, in sum, the Soviet leadership has been its own worst enemy. Crude pressures and blatant propaganda combined with the itch to pick up whatever small change was available to align much of the world against Moscow. But a sophisticated Soviet leader, if he softens the system, can change the climate. Where the machine failed, a man can succeed.