LAST YEAR the Group of Seven took up aid to Eastern Europe, and such has been the rush of events that this year these leading industrial democracies will try to work through the merits of aid to the Soviet Union. The idea languished through the spring; democratic governments could not countenance aid to the Kremlin while it was throttling Lithuania. But with tentative signs that Mikhail Gorbachev is looking to a looser new federation to contain ethnic strivings in the Baltics and elsewhere, French President Francois Mitterrand has asked the approaching G-7 summit to consider ''financial, commercial and technical aid'' to enable Mr. Gorbachev to sustain de'tente and reform -- cheap at the price (about $20 billion), it is argued. The proposal may gain some momentum at the 12-nation European Community summit in Dublin on June 25-26 before the G-7 gathers in Houston on July 9.

President Bush is taking an accommodating stance, saying he's ready to talk. Plainly, he realizes that powerful economic as well as political currents drive the West to engage, and he does not want to see a gap open on this issue or to lose the opportunity to steer the process. Separate parts of the discussion have already begun. For instance, some American taps would be opened as soon as Soviet policy on Lithuania and Jewish emigration meet Congress' terms for putting into effect the trade agreement that Mr. Gorbachev signed in Washington. But as commonly used, ''aid'' covers a multitude of economic transactions along a broad spectrum ranging from official-concessional to private-commercial, and G-7 consultation is overdue.

Mr. Bush leans to transactions at the commercial end. That instinct is sound. Let commerce go forward. But concessional aid without reform -- reform of the profound society-racking sort that East Europeans are attempting and the Soviets are not -- is economically dubious. Concessional aid to a country that still manages to afford not only great military deployments but also huge subsidies to unelected regimes in Cuba and Afghanistan is politically dubious. Concessional aid that might otherwise go to struggling democracies -- in East Europe, Central America or Namibia -- or truly poor nations in the Third World is morally dubious. These are the considerations that must be weighed against the undeniable Western interest in seeing Mr. Gorbachev's good policies succeed.