For years, Ronald Reagan has been polishing a passionate faith in the ways of American democracy and free enterprise. Long the basis of his personal belief, it is now the core of his administration's official ideology. Foreigners, however, can be forgiven for having wondered just how far and deep Mr. Reagan's commitment runs--whether, in short, he actually believes it. They cannot be in much doubt after the speech he made to the British Parliament before going on, in his European tour, to tackle security issues at Bonn.

"Must freedom wither--in a quiet, deadening accommodation with totalitarian evil?" President Reagan asked. The formulation, the set of alternatives he posed, must have jarred many of his listeners. But the president was ready with an answer. Detailing the flaws of the communist system, he summoned the West to mobilize a global "crusade for freedom," a "campaign for democracy." In the Third World, it would actively foster the "infrastructure of democracy"--unions, political parties, press and universities. For communist countries, he stated suggestively and not very specifically "a plan and a hope for the long term."

It is only right, even necessary, that Europeans-- and not only Europeans--ask if Mr. Reagan's ideological muscularity masks a rededication to the excesses of military and political interventionism that many people on both sides of the Atlantic associate with the worst days of the Cold War. It would not be the first time that a decent pride in one's own values and institutions produced a skewed foreign policy. It is easy enough, too, to wonder about some of the Reagan particulars, such as his announcement that the American political parties are going to study whether they can openly help foreign counterparts in the way the big European parties have done for decades. For some of us, the American political parties, at the moment, would seem to need help more than they need to dispense it, but never mind.

There are a dozen ways to overdo it, but perhaps there are one or two good ways to do it right: to encourage American free institutions, which already do some missionary work, to do more. Democracy is not a fragile flower, Mr. Reagan correctly says; "still it needs cultivating." For some time in this country an argument has been taking place on how it might be cultivated more effectively: by example or by direction, with "propaganda" or "truth," secretly or openly, privately or publicly, as complement to or substitute for other policies, in this group of countries or in that group, and so on. That argument can now go international.