ARE THE "NONALIGNED" countries, or a number of them, losing some of the softness for Moscow that has so often made it necessary to put quotation marks on their professions of nonalignment? At the Belgrade meeting of 80 or so nations that claim to sit apart from the American-and Soviet-led alliances, a major argument arose between Yugoslavia and Cuba. Yugoslavia's President Tito said in effect that non-alignment remains a viable international policy and the principal threat to it comes from great-power intervention conducted by the Soviet Union and Cuba. The Cuban foreign minister said in effect that nonalignment should foster liberation and revolution, as defined by Havana and Moscow. The weight of the conference seemed to be on the Tito side.

The Belgrade session made plain the way many Third World countries feel about having disputes in their midst resolved by foreign forces. A lot of members, press reports said, warned they might boycott the nonaligned summit next year in Havana if the Cubans don't quit Africa. There seemed to be a strong awareness that, while a country has a right to ask for foreign help in a crisis, use of that right can produce harmful local and great-power tensions and can diminish the incentive to go for a political settlement. In the latter regard, it is noteworthy that at Belgrade Angola and Zaire said they had agreed on a kind of nonaggression pact; had it been in effect earlier, there might have been no Shaba crisis.

The larger perception that seemed to be moving ahead at Belgrade concerned the new dangers that lurk for nonaligned countries. Ten or 20 years ago it was easy for most of those countries to identify the peril as "imperialism." But even the harshest critics of the United States see that it no longer has the same taste or capacity to intervene. Meanwhile, the Soviet Union, using Cuban soldiers, is flexing its muscles. Many people, looking at the Third World, see a vista of unrest, turbulence, ethnic challenges, class wars, regional upheavals and what have you. Nonaligned people perhaps see that vista more clearly, and with more horror, than the rest of us. To them, or to an increasing number of them, communist intervention means not help but trouble.

Well, you may say, all they did at Belgrade was talk. True. One can't know what it means until a secession movement gets rolling somewhere, or an ethnic minority demands independence, or a "treasonous" faction seizes the telegraph office or . . . Certainly there's nothing for Americans to take premature or conspicuous delight in. But it's an interesting development, all the same.