Now on both sides of the Atlantic the weapons of war have been enlisted to wage peace. First America's European allies called for deployment of US nuclear missiles on their soil - but only in conjunction with vigorous arms control efforts intended to make deployment unnecessary.
At this moment members of the US Congress are using similar tactics. They are willing to fund a step toward MX deployment on American soil - but only in conjunction with similarly vigorous arms control efforts on the part of the administration.
President Reagan this week responded to Congress in writing, just as he earlier had spoken to assure the Europeans of his willingness to be flexible for the sake of achieving arms control. He can dispel the immediate cry of ''smokescreen'' from a leading congressional opponent of MX; all he has to do now is follow through with actions as dedicated as his words.
Mr. Reagan can rightly argue that arms control is a two-way street. It is up to the Soviets, with their absurdly excessive SS-20s aimed at Europe, to forgo propaganda for progress in the Euromissile negotiations. And they do not inspire confidence in their START overtures on strategic arms when they test a missile that brings questions about whether it violates the unratified SALT II treaty to which both sides have supposedly been adhering.
Moscow will be under greater pressure to join the arms control effort if it faces negotiators with united resolve behind them - rather than lonely voices with constituencies as badly split as Moscow would like.
Therefore Mr. Reagan is on the right track in seeking a realistic linkage of arms and arms control policies to unite his constituencies both in Europe and in his own nation.