THE West is facing a first critical test of its commitment to help the former Soviet republics get back on their feet economically. The Russian winter is approaching, and the food picture is grim: a small grain crop and a distribution system that's creakier than ever.Immediate help is needed to ensure that enough basic foodstuffs reach the republics to head off hoarding and hunger. If aid doesn't flow, political unrest could flare, igniting a possible backlash against reform and increased refugee flows. In letters to the European Community and Group of Seven industrial nations, Mikhail Gorbachev has asked for $7 billion in donated food. That goes well beyond the aid so far generated in the West. The EC is already committed to ship $300 million in free food. Both the Europeans and the US have programs for hundreds of millions in loan guarantees to enable Moscow to buy more food. The loan guarantees have run into a problem, however. Commercial bankers aren't interested in dealing with Moscow even if Washington stands behind the loans. The Soviets were bad risks even before the August coup; that episode and its aftermath made the banks more skittish than ever. And what about the distribution system in Russia and the other republics? It's in worse shape now than a year ago, when it failed to get an ample crop to market. Mr. Bush is sending delegations from the US Agriculture Department to assess these problems and suggest ways of solving them. That kind of study will be important in helping the republics address long-term needs for modernization. Teamwork with Western corporations experienced in food production and processing will also be useful. But what's needed right now are ways of getting food aid on its way. If loan guarantees don't work, then other mechanisms - perhaps laws that allow for quick emergency relief - should kick in. The EC is exploring the idea of buying surplus food from producers in Eastern Europe and shipping that east. Food aid adequate to see the newly sovereign republics through this winter is a relatively small investment. Its yield could be large: better prospects for stability and economic development.