The rising tide of opinion now holds that the Kremlin move into Afghanistan portends or registers a shift in the global balance of power. Some people say it with a certain exultation, hoping the news will galvanize us, and others with a shudder. But either way, I think, it is a faulty analysis. The Soviet move is one of many moves by many actors in a kaleidoscopic world. Some work against us, some for. We have enough legitimate things to worry about without piling up exaggerated anxieties that can have the harmful effect of spurring us to questionable strategic exertions and adding gratuitous increments to our despair.

Now, Moscow has done something truly ugly in Afghanistan, and Americans should be careful not to make up excuses for it. What you might call the salmon syndrome -- saying that oh, well, Russionas have always has a thing about reaching warm water -- is one excuse. Suggesting that the Kremlin was motivated by seemingly genuine Soviet "national interests," as distinguished from an unacceptable greed, is a second. Observing that SALT was in trouble in the Senate, so how can you expect the Russians not to pick off a plum, is a third.

To say, however, that the Soviet Union has the itch to be irresponsible and that global turbulence promises to provide it continuing opportunities does not mean the United States cannot hold up its end. Such defeatism hovers behind much hard-line comment.It is unbecoming, demoralizing and inaccurate. It simply is not so that we cannot tend fairly to our world interests.

It has become customary for conservative critics of policy to back off a step and become critics of the American character. (Jimmy Carter succumbed to a form of this weakness last summer when he confused his own inadequacies with a national "malaise.") These critics tend to locate the source of the trouble in a failure of national will.

It follows that the remedy is a rude awakening: SALT should be defeated not just because the treaty is flawed but because the American people must be jarred out of a perilous complacency. The presidient should have been readier all along to use force in Iran, it is suggested, not because it would reclaim the hostages but because the American people need to be blooded, to have their tase fro struggle and sacrifice sharpened.

I am not one to repose mystical faith in "the people." That is being sentimental and it lifts responsiblity from where it ought to be -- on the politicians entrusted with power. I simply think that, given everything, we are entitled to view our current predicament in less than apocalyptic terms.

The Soviet Union has made headway of different sorts in Afghanistan, the Yemens, Ethiopia -- all places uneasily close to our whiny Persian Gulf oil friends. But meanwhile, the United States has held or improved its position, in different ways, in China, the Indian Ociean area and parts of the Mideast, and elsewhere. Who would feel better if Moscow had knit up ties with Peking and we had picked up Kabul?

In Europe, NATO has just decided, in the teeth of massive Soviet pressure, to support missile modernization -- a historic decision belying the allies' alleged "Finlandization." In southern Africa, British diplomacy has just consummated an American conception of multiracial coexistence in a no less historic development whose promise is nothing less than to defuse an entire region of conflict. Our Persian Gulf cares at least let us see how manageable by contrast are our Latin-Caribbean concerns.

My point is that although the ostensibly hardheaded conservatives among us are prone to fits of panic and self-doubt, the rest of us should realize that the United States can compete. We need huge Manhattan Project military or diplomatic programs. We need, particularly around the punky Persian Gulf, carpentry. Moreover, mush of it is now going forward -- in defense spending, arms deals, base arrangements, etc. It won't ensure us against every fresh upheaval, but it will keep us in the game. To ask for more is immature.

In strategic terms, we are worst off precisely where the hard-liners raise the hottest alarms: in arms control.The country would be far better off navigating in this unkind world if Soviet strategic programs were under even the incomplete constraints of SALT II. The hawks' lack of cool may be taking its heaviest toll there.

But all of us have some hard work ahead on the single thing that would most ease our way in the world: a sensible energy policy. On that prime issue, no amount of geopolitical mumbo-jumbo and evocation of a Soviet threat can save us from ourselves.