Brussels — An agreement expected to be reached here next month among NATO countries could rekindle the debate over whether America's European allies contribute enough to the defense of the West.
Some officials say the accord - on NATO financing for military support facilities in Western Europe - could provide proof that America's European partners are prepared to do more. Others say it will reveal continuing differences between the two sides on the question of defense.
Last June, the United States Senate reflected deep concern in the country over Europe's contribution to Western defense when it only narrowly defeated an amendment calling for the gradual withdrawal of 90,000 US troops from Western Europe if European governments failed to increase military spending.
Those supporting the amendment said the Europeans should spend more, for example, on support facilities to be used by US troops in the event of rapid deployment to Western Europe at a time of crisis.
Last May, NATO defense ministers failed to agree on new ''infrastructure'' funding for the next six years and instructed their representatives meeting here in Brussels to resolve the dispute (essentially between the US on the one hand, and its European allies on the other) by mid-August.
Despite head-to-head talks in Washington in July between US Defense Secretary Caspar Weinberger and West German Defense Minister Manfred Worner, that deadline passed. A new deadline of Sept. 30 has been set.
The dispute over NATO's infrastructure budget concerns principally the US and West Germany, which together pay more than half the bill.
NATO's military commanders said originally that they needed $14.6 billion to improve European infrastructure facilities between next year and 1990. That figure was eventually pruned back to about $10 billion.
But the Bonn government balked, saying it could agree to no more than about $ 6 billion. Its position was supported by the majority of European governments which, like Bonn, cited national budgetary constraints.
Talks here dragged on for weeks without any sign of agreement. Then, just before the summer recess in mid-August, it became clear that Bonn and Washington were nearing agreement on a compromise of about $7.85 billion.
Whatever figure the NATO allies finally agree to is unlikely to satisfy military people on either side of the Atlantic. Whether it will appease critics of the European defense effort in the US remains to be seen.
So far, moves by the Europeans to show their US ally that they have been shouldering their fair share of the alliance defense burden have proved largely ineffectual.
A public relations campaign launched last year by NATO's European members, for example, seems to have fallen on deaf ears in the US.
A slick brochure published as part of the campaign by NATO's so-called Eurogroup said US criticism of Europe's contribution to Western defense was unfair. It said, for example, that during the 1970s, European governments increased their total defense spending in real terms (i.e., after inflation is taken into account) by 2 percent a year while the US cut defense expenditures by more than 1 percent a year.
The pamphlet, quoting a March 1982 report to Congress by Mr. Weinberger which said that ''the non-US NATO allies in aggregate appear to be shouldering roughly their fair share of the total defense effort,'' went on to say that European governments provide more than 80 percent of the ground forces, combat aircraft, tanks, and armored divisions stationed in Western Europe during peacetime.
At sea, the Europeans provide about 70 percent of the fighting ships, the pamphlet said.
Public attention will be focused on NATO's infrastructure facilities - and by implication on the funding necessary to support them - in September when thousands of US troops are moved to Western Europe as part of NATO's annual Autumn Forge exercises.
Among other things, these maneuvers, which involve military units from most NATO countries, are designed to test the ability of facilities here to receive a massive influx of US troops during a time of crisis.