Trouble in the Pacific.

TO WEST EUROPEANS, the Pacific seems impossibly distant, militarily speaking, whereas to Americans it is on their western doorstep. Yet history has left its legacies: The British are aware that they have distant cousins in Australasia, especially when cricketing tours are in the news; and the French still have a few Oceanic specks under their flag, such as Gauguin's Tahiti and New Caledonia.

Suddenly, Oceania is in crisis. To be precise, two crises are unfolding: in New Zealand's relations with the U.S., and in France's relations with rebellious locals on New Caledonia. The two situations are linked, and not only by geography. From the standpoint of this column, the key common factor is the nuclear question.

The recently elected Labour prime minister of New Zealand, Mr. David Lange, wants U.S. naval ships carrying nuclear weapons to stay away from his shores and harbors. The French understand that if they should give independence precipitately to New Caledonia their use of Mururoa as a testing ground for their nuclear weapons would soon be denied, and with that denial France's claim to be a nuclear and global power would vanish.

Military pacts survive to the extent that their members continue to believe that their national interests are thereby served. The ANZUS Pact between the U.S., Australia, and New Zealand came into force on April 29, 1952, and is thus of Korean War vintage. In the 1950s, remember, international Communism was still monolithic, and Stalin was able to fight the U.S. and its UN allies to the last North Korean and Chinese "people's volunteer." ANZUS was part of a pattern that included defense deals with the Philippines, Taiwan, South Korea, and (in 1960) Japan; and of course the now defunct SEATO, enshrined in the Manila Pact of 1954.

Much has changed since then. SEATO started eroding when the French stopped attending its meetings, and it ceased to have much meaning when they and the Pakistanis withdrew. It was disbanded in 1977. Other events that left their mark include the Sino-Soviet rift and the Vietnam War.

In these changed circumstances, the New Zealanders who voted Mr. Lange into power last July were aware that, while reaffirming loyalty to ANZUS, he would ban nuclear-powered and nuclear-armed ships from New Zealand waters. Is Mr. Lange's position tenable?

Personally, I don't think it is. Either little New Zealand (population 3.3 million, armed forces 12,000-plus) is a member of the ANZUS club, accepting U.S. protection, or it is not. Whether the U.S. has overreacted to this challenge by curtailing defense cooperation with Wellington is a matter of opinion. It is illogical for Mr. Lange to complain.

Fortunately, the Australian prime minister, Mr. Bob Hawke, although also of the Labor persuasion, has a far more robust approach to common defense problems. In both countries, of course, the growth of nuclear pacifism is closely linked with that of Moscow-sponsored "peace" movements.

THE CRISIS IN New Caledonia is of a unique character because of the unusual ethnic composition of the population. Although the Melanesian Canaques or Kanaks (or those who speak in their name) are calling for immediate independence, they constitute only a minority of the population (sixty thousand out of 145,000), although the largest single group. Some 52,000 Europeans live on the islands; there are also some 12,000 tribalized Melanesians and seven thousand Polynesians. To add to the blur, there has been extensive cross-ethnic breeding. Thus Jean-Marie Tjibaou, the leader of the most militant of the independence groups, the Kanak Socialist National Liberation Front (FLNKS), may think of himself as a Melanesian but cannot disguise his Japanese ancestry.

The New Caledonia crisis seems to have taken President Mitterrand's government utterly by surprise. Inspired, as socialists often are, by impeccable sentiments, it recognized the "innate and active right of the Canaque people to independence." That was in July 1983. Last October, a group of the most radical "independentists" traveled to Paris, then flew to Rome--and vanished. Back in Noumea, some weeks later, they revealed that from Rome they had gone to Tripoli to get aid and advice from the ever understanding Colonel Qaddafi. They were good learners. On November 21 they seized the town of Thio and held the inhabitants as hostages for a month.

Taken aback, Paris dispatched a small force of gendarmes, but gave them orders to stand idly by (while rape and pillage went on). Mitterrand, noting that the French High Commissioner in New Caledonia, M. Jacques Roynette, was out of his depth, sent a former Gaullist minister, M. Edgard Pisani, with an offer of "independence in association with France." One would have thought this formula had been sufficiently discredited by the Bao Dai experiment in Indochina. Predictably, it was summarily turned down.

The gravity of the crisis then hit Paris: no New Caledonia, no more Oceanic possessions, no more nuclear tests, end of France as a nuclear power? As I write these lines, no solution is in sight. I just add, to provide the missing spice, that one of the independence groups, the Kanak Socialist Liberation (LKS), is Marxist-Leninist and that the French Revolutionary Communist League (LCR) has been pretty active down there. Understandably, the U.S. has been advising Mitterrand to take a strong stand and go easy on independence.