There are growing indications that the Falkland Islands crisis may come to a head within days - perhaps this week.
British pessimism about the state of negotiations and the recall of British ambassadors to the United Nations and Washington have heightened speculation that Prime Minister Margaret Thatcher's patience with diplomacy is wearing thin. This is true even though Britain's ambassdors to the UN and Washington are returning to the United States Monday to resume negotiations.
If it has, and if there is no quick resolution of the problem at the UN, a major British invasion of the islands becomes increasingly likely. Two limited British attacks over the weekend were interpreted by some as possible preludes to invasion.
Britain's recourse to relatively minor military operations so far is thought to be in part due to its desire not to upset its European partners, which have been urging Britain to exercise restraint.
At its May 17 meeting in Luxembourg, the European Community (EC) is expected to extend the sanctions it imposed on Argentina a month ago, says British Foreign Minister Francis Pym. A preliminary meeting May 16 ended without a decision being taken.
With this crucial decision now out of the way, the expectation was that Britain might feel less inhibited to launch a full-scale invasion.
While both Britain and Argentina are careful not to exclude the possibility of a negotiated settlement at the UN, there is growing concern that time is running out. On all sides there is a realization that this week is critical in finding a diplomatic way out of the impasse. Unless a settlement is reached by the middle of the week, fighting on a much larger scale could result almost immediately.
The view of military analysts (a view Mrs. Thatcher is keenly aware of) is that with the bulk of the British task force now in place, the Royal Navy cannot indefinitely postpone action if a diplomatic solution isn't found quickly.
A long vigil at sea is expected to take the fighting edge off the British unless they can soon go ashore. Equally troubling to the Royal Navy is the realization that that with rapid onset of winter, icy seas could also take their toll. Conditions have already deteriorated since Argentina seized the islands April 2. For these reasons, Britain's military strategists feel it is imperative that action be taken soon or the lives of their own men will be put in jeopardy.
British Defense Secretary John Nott appeared to be speaking for a majority of Mrs. Thatcher's Cabinet when he implied that a frontal assault on the Falklands Islands was likely this week.
Spokesman for the government deny that a split has opened up in the Cabinet because of an apparent divergence between Mr. Nott's more hard-line position and Foreign Secretary Francis Pym's determination to push for more negotiations at the UN.
At the same time Mr. Pym's position seemed to erode as UN talks made only limited progress and pressures for a determined British landing on the islands continued to build.
Said one British defense source, ''Tuesday or Wednesday of this week will see the British task force in a strong position to mount an assault. Delay for a further week would probably mean the opportunity being lost.''
The counter-argument, which finds an echo in Foreign Secretary Pym, is that Britain might lose international support by mounting an assault on the islands while UN talks are proceeding.
Optimism that UN talks were bearing fruit faded at the weekend with London's apparent insistence that residents of the Falklands play a role in the interim administration of the islands while a long-range future was being decided.
For the past month the Europeans have been backing Britain with economic sanctions against Argentina. The decision was taken with surprising unanimity and alacrity. But since then, British retaliatory measures against Argentina - such as the May 2 sinking of the cruiser General Belgrano with the loss of more than 300 lives--have caused dismay in Europe and produced more qualified support for London's position.
The EC meeting on sanctions today is expected to stress that Britain must now put the emphasis on finding a diplomatic solution to the crisis or put in jeopardy continued European support.
Officials in Luxembourg where EC foreign ministers met May 15 point out that while some European countries remain skeptical about the effectiveness of trade sanctions, and wonder in fact that they may be exacerbating the conflict, the EC had no choice but to extend the ban. To have dropped it now, the officials argue , would have been interpreted--not least of all by the Soviet Union--as evidence of Europe's unwillingness to stand by an ally in times of crisis.
Yet even as late as Saturday it was unclear whether the EC would back a renewal or seek an end to the ban which is costing Argentina nearly $150 million in lost exports.
Ireland has come out against renewing the import ban. A strongly represented left-leaning contingent in the Danish Parliament had pressed for government opposition to the ban. Officials in West Germany had said that Bonn would reserve judgment until the last minute, and that if Britain launched an attack on the Argentine mainland, West German support for the ban may be withdrawn. Italian Foreign Minister Emilio Colombo, reflecting public concern for the fate of the large population of Italian descent living in Argentina, said as late as last week that the government remained uncommitted on extending the ban.
But on Saturday, West German Chancellor Helmut Schmidt and French President Francois Mitterrand both expressed their solidarity with Britain and said they saw no reason to halt the ban now, putting pressure on Italy to come down off the fence. Danish and Dutch reservations fell by the wayside.
Just how difficult it has been politically for some European countries to impose sanctions against Argentina--with which many countries have strong economic and cultural ties--was reflected in a reply given to an American journalist by a senior Italian diplomat. Emerging from a meeting on the issue over the weekend, the diplomat said: ''It's as hard as if your country imposed an imports ban on Canada.''
With European doubts growing, it appears unlikely that Britain can rely on unquestioning support for much longer.
For Britain's negotiators at the UN, this has meant that the pressure on them to achieve an early solution is increasing sharply. Defense Secretary Nott has told Mrs. Thatcher that the moment negotiations show signs of having reached a dead end, the task force is ready to invade the islands.
The prime minister has refused all along to accept anything short of Argentine readiness to withdraw its invading troops. The feeling in Whitehall at the weekend was that hopes of achieving this without a major military action had virtually disappeared.