The ''Historic Compromise,'' that old policy warhorse on which the Communists had hoped to ride back into the national government side by side with the ruling Christian Democrats, will be interred, quietly and almost surreptitiously, at the 16th National Congress of the Italian Communist Party in Milan (March 2 to 6 ). There will be no tears, regrets, or eulogy, however, for the congress is not called upon to mourn the passing of an old policy but to celebrate the birth of a new one from its ashes.
Secretary General Enrico Berlinguer will formally announce to his congressional delegates that the road to national power must be fashioned, henceforth, against and without the Christian Democrats, not in partnership with them as he had urged, long and hard, before. To that end, he will ask the congress to endorse his new course, and will, at the same time, invite the Socialists and other leftist forces to joint the Communists in the creation of a government of ''Democratic Alternative'' to perennial Christian Democratic rule.
Berlinguer's new strategy had been gestating as far back as 1979-80 when pursuit of the Historic Compromise proved inconclusive and too costly both in terms of votes and internal party harmony. It not only represents a radical reversal of his earlier policy of rapprochement with the Christian Democrats but , even more important, reflects a new-found confidence in the political viability of his claim to national power. For, if it is true that Historic Compromise failed to bring the Communists into the national government, it is equally true that it brought them close enough to it, during nearly three years of participation in the government's parliamentary majority, to win them spurs as legitimate candidates to eventual governance.
Lest it be forgotten, the Historic Compromise was predicated on Berlinguer's often-expressed fears - real or feigned - that accession of the Communists to a national government which excluded the Christian Democrats would pre-cipitate, in his words, ''a Chilean solution,'' i.e., a right wing backlash similar to the one that toppled the leftist regime of Salvador Allende in 1973. Berlinguer's bold new decision to seek power without and against the Christian Democrats can only lead to the inescapable conclusion that he now believes that the political climate, both domestic and international, poses little or no risk to an eventual Communist-dominated government in Italy. It may not be pure coincidence, perhaps , that Berlinguer's new course is becoming official party policy at a time when Communist participation in the French government is accepted with remarkable equanimity both at home and abroad.
From the pre-congressional debates among the Communist rank and file, it is clear that Berlinguer will have little trouble winning a resounding endorsement for his new ''Alternative'' policy. Envisaging an alliance with the Socialists and other leftists, it is more congenial to Communist orthodoxy than his earlier proposal for a partnership with the Christian Democratic bourgeois enemy.
It is equally clear, however, that any effort on his part further to dilute party ideology or to escalate condemnation of Soviet policies and dissociate the party from them will be resisted by the small but militant ''pro-Soviet'' wing of the party, led by Armando Cossutta. Berlinguer must weigh the desirability of making some peace offerings to his internal opposition for the sake of party harmony (in lieu of imposing compliance through the application of democratic centralism) against the need further to distance himself from Moscow in order to enhance the credibility and acceptability of his new course amoung potential new voters and political allies.
His anticipated triumph at the Congress notwithstanding, the success of Berlinguer's new strategy rests ultimately on his ability to wean the Socialists and the other democratic left-oriented forces away from the Christian Democrats. For the chances of the Communists parlaying their present 32 percent of the parliamentary seats into an absolute majority at the next general elections are, given the notorious impermeability of the Italian electorate to drastic shifts, extremely remote.
The Christian Democrats have accepted Berlinguer's challenge and have recognized that the two parties are, in the words of their new leader, Ciriaco De Mita, ''culturally, historically, and politically incompatible, and hence, alternative to one another.'' De Mita has offered the Socialists and the smaller parties which currently participate in or support Premier Amintore Fanfani's government (Social Democrats, Liberals, and Republicans) a long-term partnership , good for the present and subsequent legislature, i.e., for almost seven years. Not bad in a country where the average lifespan of a government is roughly seven months.
The political alignment that would constitute Berlinguer's ''Alternative'' does not now command a viable majority in parliament. A leftward shift of a few percentage points in the next general elections, however, would provide the necessary margin. At a minimum, such a result would give Berlinguer a competitive toehold vis-a-vis the Christian Democrats in the postelectoral bargaining for government allies.
In the final analysis, the viability and the eventual success of the new Communist strategy lie in the very novelty of its promise: an unprecedented change of the guard in Italy, the only West European country yet to experience one in the postwar period. Berlinguer is gambling that after nearly 40 years of uninterrupted Christian Democratic rule, Italy is finally ready for a change.