Athens — Almost two months after Cyprus's Turkish-Cypriots declared independence, arousing virtually universal condemnation, the parties to the dispute have launched yet another diplomatic offensive to solve the Cyprus problem once and for all.
That offensive, however, is troubled by the question of what role the United States ought to play.
On the Greek and Greek-Cypriot side, the belief is that although only the United Nations can successfully mediate a solution to the division of the island , UN efforts cannot bear fruit unless the US pressures Turkey to make concessions.
Turkey's invasion of Cyprus in 1974, according to a Cypriot diplomat in Athens, was carried out with US equipment.
''The US had warning and could have stopped it. Only the US can press Turkey toward the political will to move on Cyprus,'' the diplomat said.
On the other side, the Turks and Turkish Cypriots warn that the two communities must solve their problems directly. US pressure ''would bring serious consequences,'' according to Turkish-Cypriot leader Rauf Denktash. ''A repeat of the (US) embargo (against Turkey) will only please the Greek lobby but will mean an infringement of US interests'' in the eastern Mediterranean, he added.
So the US finds itself caught in the middle. US diplomats say that to pressure either side would be ineffective - as was the US embargo against Turkey imposed after the 1974 invasion and later lifted - and do serious damage to US interests.
If it does nothing, the officials maintain, the US would anger the Greeks and perpetuate a dangerous status quo.
''If we could solve the problem,'' a US diplomat said, ''it would be a positive development for the US with both Greece and Turkey, NATO and Congress.''
In the last two weeks, both sides have launched new efforts designed to seize the diplomatic initiative. Aside from warning the US to remain neutral in the dispute, Turkish Cypriots have offered to reopen the international airport of the divided capital, Nicosia, to make a special effort to account for some 2,000 persons missing since 1974, and to allow Greek Cypriots to return to Famagusta - occupied by Turkey during the invasion and once the hub of the island's tourist trade.
The offer has been rejected as a ploy by the the Greek Cypriots who believe that outside the framework of an overall settlement it would only legitimize the present situation.
Ankara has also proposed to remove 1,500 out of 20,000 of its troops from the island. Greek-Cypriot officials have dismissed the proposal as a meaningless gesture meant only to curry favor with the international community.
At the same time, Greek Prime Minister Andreas Papandreou has been meeting with Greek and Greek-Cypriot political leaders, including a recent visit with Cypriot President Spyros Kyprianou, to provide momentum for Greek and UN efforts.
Mr. Kyprianou plans to meet with UN Secretary-General Javier Perez de Cuellar and senior US officials, perhaps including President Reagan, during a trip to the United States.
There is little indication that these efforts will lead to the reunification of the island any time soon. Constitutional disputes have repeatedly caused tensions, and often violence, between the two communities since the island became independent from Britain in 1960. The invasion and subsequent division is only the most dramatic manifestation of the problem.
What seems certain is that the US has at least as much to lose as it has to gain in Cyprus. And only subtle, skillful diplomacy will make the latter rather than the former possible.