An in-house feud that weakens NATO in Europe, Mideast

In this late summer of 1980, as in that of 1956, The Western world suddenly finds itself facing simultaneous challenges in East Europe and the eastern Mediterranean.

For NATO defense planners, Greece and Turkey now hold some of the main keys to meeting both challenges successfully.

Planners at NATO's southern European headquarters are comparing the present Polish crisis with the prologue to the Budapest uprising of Hungary's freedom fighters in 1956. The coincident British-French-Israeli military expe dition against Egypt to seize the Suez Canal and bring down President Nasser diverted United States energy and attention away from the Hungarians at that time. They were crushed by Soviet tanks.

At Suez, the US and Soviet Union found themselves on the same side of the fence. Under threats by Soviet Premier Nikita Khrushchev to rain missiles on London or Paris, and stronger pressure on Israel by Dwight einsenhower than ever used before or since by a US president, Israel and its Anglo-French allies were forced to withdraw from Egypt.

Nasser stayed in power. The Suez Canal remained Egyptian. Hungary was nailed even more tightly than before into the Soviet bloc.

The threat of a two-front crisis is regarded as real again today. A spillover of Poland's unrest into East Germany might trigger West German reaction and consequent Soviet action against NATO. Breakdown of the always shaky cease-fire between Israelis and Palestinians in southern Lebanon simultaneously threatens wider involvement of Syria.

Circumstances seem to be forcing Syria's President Hafez Assad deeper into the embrace of the Soviets. They alone are prepared to provide Syria with military aid paid for by Arab oil states.

A Mideast war would unleash Arab oil embargoes and blockades. These could bring West Europe's economies and military establishments, even more than those of the United States, to a grindling halt. NATO's task of resisting Soviet pressures would become almost impossible. With divided energies, the West, as in Hungary and Suez, might find it difficult to cope effectively.

This two-crisis situation has caused US Army Gen. Bernard W. Rogers, who wears two hats as supreme American and NATO commander in Europe, to redouble patient efforts begun by his predecessor, Gen. Alexander Haig.

The aim is to heal the fractured link between NATO and the Mideast: the Greek-turkish dispute.

Greece and Turkey now are objects of intense efforts by General Rogers and his staff to cool their centuries-old feud sufficiently to allow Greece to resume full NATO participation. Greek President Constantine Caramanlis, then prime minister, took Greece out of most NATO military activities in 1974 in anger over Turkey's invasion of Cyprus.

Under discrett US pressure, talks in Cyprus for the elusive settlement between the Greek and Turkish Cypriots are scheduled to resume Sept. 15. Meanwhile, Mr. Caramanlis and Prime Minister George Rallis have served clear notice that if Greek-Turkish differences over command and control in the Aegean Sea and airspace are not overcome soon, Greece will close its US bases, since these are supposed to operate only in a NATO framework.

The Greek bases are doubly important to the US now. In turkey, Prime Minister Suleyman Demirel's government, hard-pressed by terrorism and bankruptcy , has repeatedly made it clear that US bases there are off limits to any US forces engaged in non-NATO operations. This means anything not involving a direct Soviet attack on Turkey, which no one in Turkey considers at all likely.

Mr. Demirel has specifically ruled out, for example, use of the big NATO air bas at Incirlik for US operations against Iran and by implication, for support of threatened Arab regimes in the Gulf. Resupplying of Israel in any new war with the Arabs would also be ruled out, as in 1967 and 1973.

If either Poland or the Mideast triggered a Western-Soviet conflict, Greece and Turkey, standing together could bar the Soviet pathway to the Mediterranean and the Turkish straits, which President Harry Truman in 1948 protected from Soviet dictator Joseph Stalin's open takeover bid. Mr. Truman's decision began the long presence of US forces in Greece and Turkey that continues today.

Greece insists that it must control the air space over and around its eastern Aegean islands, which hug Turkey's coast. Turkey argues equally strongly that its own air defence zone should begin in mid Aegean, well west of the islands. This leaves command arrangements hopelessly snarled. Both Athens and Ankara might be willing or unable to carry out emergency NATO defense orders.

A Warsaw Pact thrust to the Aegean could never succeed without crossing the slender band of Greece and Turkish Thrace protecting Turkey's critical straits. Likewise, as a NATO memorandum for US congressmen puts it:

"All major land, sea, and air routes from the Black Sea to the Mediterranean and from the Belkans to the Persian Gulf lead across Turkey."

Together, Greek and Turkish forces tie down about Sea, and Balkans. Either Greece or Turkey standing alone would be cut off and isolated from the rest of NATO. The Russians could deal with revolts or other emergencies in East Europe without fear of difficulties on their south European flank.

Unless Greece and Turkey cooperated closely with US, Italian, and British forces in the Mediterranean, allied operations against the strong Soviet fleet in the Mediterranean, and allied control of sea lanes from the Atlantic to the Mideast would be extremely difficult.

(France's forces are a question mark because France, like Greece, left the NATO command some time ago.)

More than this, uncertainty over the future of US intelligence monitoring sites in Turkey, which watch Soviet missile tests and troop movements, makes retention of similar installations in Greece and Crete, imperative from the US, as well as the NATO, viewpoint.

Thus, in his race against the ticking countdowns in Athens, Ankara, Jerusalem , Damascus and Warsaw, General Rogers faces a formidable task.