The intriguing feature of Reagan foreign policy these days is that the alarms and complaints about it emanating from the right are so much more shrill than those coming from the left. Hardliners fear that in arms control, as in Nicaragua and other regional disputes, the president, influenced by diplomats and do-gooders of various stripes, is selling out his conservative inheritance. The liberals very much doubt it, but, recently anyway, they've been making less noise.

In fact, the president's policy is in a revealingly indeterminate place. He is poised between his premises and the possibilities in the real world. His premises rest on the expectation of protracted ideological conflict. But, fortunately, he does not simply put policy on automatic pilot. He must also acknowledge the possibilities in the real world, possibilities that include not only dangers but opportunities for at least temporary and partial accommodation with the devils in Moscow. What is it going to be for Ronald Reagan, who does not have all the time in the world?

No wonder the sense spreads that this is the opportune moment to persuade him to fulfill either his hardline potential or his pragmatic potential. Although it seems obvious that the hardline potential is much more within his grasp, he could go either way. He could also, of course, do the easy and probably popular thing -- muddle through, which in his case would mean going more or less with the hard line.

On the right, in any event, two tendencies vie. A lot of conservatives are visibly pained by the thought that the pragmatists are subverting the original Reagan grand design. They would prefer the president to remain devoted to ideological purity, and they are afraid his head is being turned by the illusion of going down in history as someone who made some practical arrangements with the Russians.

Other conservatives look hopefully at Ronald Reagan's recent assertions of military power and his no-concessions stance in arms control and rejoice that at last "Reagan is Reagan," as the Heritage Foundation's National Security Record exulted this week.

* Meanwhile, the Trilateral Commission, a moderate-conservative organization once considered so suspect that George Bush resigned from it, has just produced a major report on "Prospects for East-West Relations" that broadly hails the administration's progress and declares with cautious relief that "the recent period has demonstrated that a hard core of mutual interests has survived a very hostile passage." The progress it hails is not just the Soviet-American return to the arms control table but the Reagan military buildup, "which has been central to the administration's East-West strategy." The Trilateral Commission even has a good word to say about a certain version of Reagan's Strategic Defense Initiative.

Can it be that Ronald Reagan is headed toward the hard right, as Heritage suggests, and toward the center, as the Trilateral Commission suggests, at the same time?

Well, yes. He is getting tougher and hanging tough in some matters, and putting himself in a position to move toward more moderate positions, at the same time. Broadly speaking, the president has built up a position of strength, and now he must decide the hardest question of his presidency, which is whether there is a suitable way to face Moscow and to trade off some of the gains he has won in confidence, credibility and power for a semi-accommodation -- a full accommodation is out of the question -- that is in the American interest and that can last.

Vintage conservatives -- surely Heritage fits here -- do not think such an accommodation can be reached and feel that the very reach is dangerous and debilitating. They posit not so much an unchangeably evil communist system as an ultimately redeemable system, one finally capable of being bent to the American will. The first is at least plausible. The second indicated incurable romanticism even before Gramm-Rudman-Hollings kicked out its financial props. This is the position that one hopes Reagan will manage in his fashion -- pretending otherwise -- to set aside.

The Trilateral Commission report is more modest and more sensible. It concludes that "the West is currently in a favorable historical position, and with imagination and skill a better relationship with the Soviet Union can be reconstructed." Noting that the Gorbachev group apparently wants a breather for domestic renewal, the report warns of a Soviet strategy "that seeks to use an interval of relaxation to rebuild Soviet power and, probably, to resume a more offensive policy." To me, this is the way to go: forward, with eyes open.