By Suneel Ratan

(FORTUNE Magazine) – Of all the foreign policy challenges likely to force their way onto President Clinton's brimming plate, none will be more critical than how to ensure the survival of Boris Yeltsin and the reforms he champions. Some advice:

-- Send more cash -- but don't go overboard. Much of the $10 billion in loans and grants that Russia received from the West last year went for food and other basic goods. That's akin to buying fish instead of a fishing rod -- and while times may be hard, Russia is not Somalia. As Robert Strauss, just back from a 15-month stint as U.S. ambassador to Moscow, says, ''We need to be engaged, but that doesn't mean throwing large sums of money around.'' Instead, the seven leading industrial countries, along with the International Monetary Fund and World Bank, should focus on supporting essential infrastructure projects, such as a modern telecommunications system and, most important, the creation of a social safety net. Harvard professor Jeffrey Sachs, a top adviser to the Russian government, thinks a decent unemployment and pension program will require $8 billion in Western aid in 1993. Says Dauphine Sloan of Washington's Center for Strategic and International Studies: ''To make the economy more efficient, there's going to have to be a lot more unemployment.''

-- Be creative and visible. As they bounce along the pothole-riddled road to free markets and democracy, ordinary Russians could use more than a cheery ''good luck'' from Western allies. A Western diplomat in Moscow suggests that the West take relatively small but symbolic steps to express sympathy and give encouragement. Example: Public transportation has all but collapsed because of poor maintenance. Why not, he says, send in 1,000 new buses? Managers who spent their careers under communist rule have a lot to learn. The U.S. Congress last year passed a bill authorizing a Democracy Corps to send volunteers into Eastern Europe and Russia and other former Soviet republics. Unlike Peace Corps members, who tend to teach or toil in low-level jobs, these volunteers would work with top managers, helping them grasp such capitalist esoterica as pricing and marketing.

-- Cut the Russians some slack. With at least 40 billion barrels in proven oil reserves and a 95% literacy rate, Russia isn't poor. But it does need breathing room on its $70 billion in foreign debt -- $30 billion of which is due in 1993. Clinton will have to twist arms in Europe, where most of those loans originated, to persuade his allies to go along. Here again, it would pay to be bold. Example: Why not tie large-scale debt relief to an agreement to destroy nuclear warheads in the enormous stockpiles of Russia and three other republics?