After nearly three years of political stability, Italian politicians seem to have decided once again to let Italy be Italy.

For behind Prime Minister Bettino Craxi's decision to submit his resignation yesterday after a postwar record of 1,060 days in power lies a revival of the traditional rivalries of personal power that brought Italy revolving-door governments since World War II -- a total of 43 before Craxi.

"This isn't a government crisis over any differences of policy or issues," said one European diplomat here who asked that his name not be used. "What we are witnessing is a pure-and-simple battle for power between two men, two parties."

Ostensibly Craxi, a Socialist who had been in office since Aug. 4, 1983, decided to resign after his five-party coalition was defeated in a secret parliamentary vote on a relatively minor local finance bill.

The defeat, by a vote of 293 to 266, represented the rebellion of about 70 coalition party deputies who, in the lexicon of Italian politics, are called "snipers" because of their attacks in secret ballots. Craxi decided the vote this time could not be ignored even though he has overlooked dozens of similar votes in the Chamber of Deputies this spring.

But the real issue, Italian political commentators seemed to agree today, was not the embarrassing parliamentary vote, but the increasingly bitter rivalry between Craxi, the Socialist, and Ciriaco de Mita, the leader of the Christian Democratic Party which, from World War II until 1981 produced virtually every prime minister.

De Mita appears determined to end the Socialists' hold on the premiership in favor of a Christian Democrat, the coalition's largest constituent party.

Craxi and de Mita, partners in the ruling five-party coalition that also includes the tiny Republican, Social Democratic and Liberal parties, have been arguing for more than a month about who should preside over the government in the last two years of the current parliament's five-year mandate.

The Christian Democrats have made it clear that they consider it time for one of their leaders to get a crack at the job. What they want is a rotation of power at the head of the coalition, which Craxi has consistently rejected.

The loss of the premiership in 1981 for the first time since the war -- to current Defense Minister Giovanni Spadolini, head of the tiny Republican Party -- was a shock to the Christian Democrats that led to the rise of de Mita as party leader -- a man who has sought to transform the image, and personnel, of the Roman Catholic-oriented conservative party under the banner of renewal.

De Mita's outright control of the party was finally confirmed last month when at its congress he was supported by 75 percent of the delegates, a previously unheard-of majority for a Christian Democratic leader.

De Mita's domination of his party set the stage for a major clash with Craxi, which erupted publicly earlier this month during the Sicilian regional elections. The two leaders sought to turn those elections into a national test of popularity and wills. The issue of party rotation was openly debated in a campaign whose bitterness far exceeded the regional issues at stake.

The Sicilian vote June 22, however, resulted in little change from one five years earlier: neither the Christian Democrats nor the Socialists made significant gains; indeed both lost votes. At the time, the Sicilian results were viewed as a vote for continuation of the coalition, not for change.

That interpretation, however, does not seem to have been accepted by the parties. The results did show some stability of voter choices, but the Christian Democrats took them as an indication that the Socialists had not gained any great popularity during their three years at the prime minister's Palazzo Chigi.

Had his Socialists posted any significant electoral gains, it is generally accepted, Craxi would have been in a position to threaten the Christian Democrats with snap national elections that might have increased his power in the coalition. Because he gained nothing, actually losing slightly from the Socialist vote in 1981, the Christian Democrats were emboldened by the realization that they had little to lose if Craxi did call for national elections before the parliament's term runs out in 1988.

"What occurred in the parliament is the logical result of Sicily's elections," Eugenio Scalfari, influential editor of Rome's daily La Repubblica, wrote in an editorial.

How President Francesco Cossiga reacts to the current crisis will not be known before early next week, when he begins consultations with political barons and party leaders.

As he did last October when Craxi offered his resignation over the controversy that followed the hijacking of the cruise liner Achille Lauro, Cossiga has asked Craxi to remain in a caretaker status until a decision on Italy's immediate political future is made.

Because the Sicilian vote indicates new elections would hardly change the balance of power, the belief is that all parties will try to avoid going to general elections now and that efforts will be made to preserve the five-party coalition that has ruled since August 1983.

That would give the president the option of asking Craxi to stay on or of seeking some sort of interim government under a Christian Democratic prime minister who would rule through the summer holidays, leaving the real issue to be decided in the fall.

The Christian Democrats have given every indication that they would agree to Craxi's staying on as prime minister if he would agree to rotating power. Craxi, however, may still not agree to giving the Christian Democrats the premiership, thus throwing the whole political equation into a disarray that only new elections could resolve.