The Turkish-Cypriot declaration of independence caught the United Nations by surprise, and brought a feeling of resignation here. Many UN diplomats are concerned that Tuesday's move by Turkish-Cypriot leader Rauf Denktash is irreversible, sets a bad precedent, and will increase international tensions.
''Whichever way you look at it, the Turkish-Cypriot secession is a slap at the international community,'' says a nonaligned ambassador. ''Like the Soviets in Afghanistan, the Israelis in Lebanon, the Americans in Grenada, the Turkish Cypriots have decided to take the law into their own hands.''
Analysts here say that:
* The Turkish-Cypriot move violates various UN resolutions that call for the withdrawal of Turkish troops from Cyprus, ask all states to respect the territorial integrity and sovereignty of Cyprus, and urge the island's two communities to come to terms.
* The move undermines UN Secretary-General Javier Perez de Cuellar's efforts to work out a settlement between the Greek and Turkish communities.
After the intercommunal talks broke down last August, the secretary-general pushed with renewed vigor to get negotiations back on track. Just last month he submitted suggestions to both sides that carefully took into account each side's minimum demands. A summit meeting was to take place early next year between Cypriot President Spiros Kyprianou and Mr. Denktash in the presence of Mr. Perez de Cuellar.
* The move is internationally divisive and fraught with dangers. Some observers think this fait accompli will split:
1. The European Community, with France leaning toward Greece and West Germany toward Turkey.
2. The Islamic nations, with Pakistan, Bangladesh, Malaysia, and Somalia leaning toward Turkey, and most of the others leaning toward Greece.
3. The nonaligned nations, which as a group warmly supported Cyprus's independence. Now it may be split down the line, with its left wing favoring Greece, its conservatives favoring Turkey, and its moderates just feeling embarrassed.
The declaration will also embarrass the United States and the Soviet Union. Neither wants to take sides to the point of endangering its relations with the other.
Turkish Cyprus, now under Turkish military protection, could eventually become a NATO stronghold. The Soviet Union would not look kindly on such a development.
Turkey is unlikely to receive West European investments and will be viewed by many EC partners with suspicion. This will not please the US, which is counting on its European allies to help put the Turkish economy back on its feet.
Historically, both Greek and Turkish intransigence contributed to the de facto partition of Cyprus. A Greek-led coup in 1974, aimed at joining the island with Greece, provoked a Turkish invasion. The Turks provided the Turkish Cypriots, who comprised 18 percent of the island's population, with 30 percent of its territory.
The UN Security Council is expected to pass without difficulty a resolution that ''deplores'' the secession, asks the Turkish Cypriots to reconsider their move, and asks all nations not to recognize the new state.
''As in so many other cases, the United Nations will express its will and then nothing will happen. Denktash will nod politely but refuse to backtrack his steps,'' said the representative of a country from the area, which enjoys good relations with Greece and Turkey.
''The emergence of a Turkish Cypriot state is going to change the political and military map of the area,'' said an official. ''It will increase East-West tensions. It will complicate life for the Balkan nations. It will pit two NATO allies, Greece and Turkey, even more than previously against each other. It will render futile the maintaining of 2,300 UN soldiers in Cyprus to prevent fighting between the two communities.''
The Turkish-Cypriot secession is a setback for the UN. UN involvement in Cyprus in the last 10 years has protected the peace. And its mediation efforts for a compromise solution have held promise.
Most analysts here say Denktash's move was prompted by the fear that further talks with the Greek Cypriots would force him to give up at least part of the territory acquired in 1974.
''He is still willing to negotiate, but only on his own terms,'' says one diplomat. ''In fact, further Greek-Turkish-Cypriot negotiations have now become irrelevant. Denktash is saying: 'Je suis, je reste' [this belongs to me and I plan to keep it].''