THROUGHOUT Western Europe this year the politicians are preoccupied by the rising economic troubles of their own countries. In each of the European capitals, as in Washington, it is the great questions of inflation, deficits and jobs that are the overriding concerns of governments. Perhaps the most important thing to be said about international relations in this season is that none of the prime ministers and chancellors is greatly concerned with them, except where they affect internal economic growth.

Germany's special torment is the tremendous budget deficit generated by the runaway costs of its elaborate structure of social benefits and pensions. For Americans, the German example is an unpleasant premonition of the shortfalls that might eventually afflict Social Security and health care systems here. Because of low birth rates in the past generation, the German population is now aging as the American population will age toward the end of the century. But Germany's Chancellor Helmut Schmidt is a Social Democrat who cannot, after all, launch his government on the kind of high-spirited budget-slashing that the Reagan administration is now undertaking. Mr. Schmidt's party does not quite have a majority in parliament, and he depends on a coalition with the Free Democrats -- liberals in the European sense -- who think that the budget deficits are dangerous and who are beginning to mutter mutinously. The life expectancy of the coalition government seems less assured than it did six months ago.

Germany's distress is, as usual, minor compared to Britain's. There the unemployment rate, which was 6.4 percent a year ago, is now up to 10.6 percent and still rising. Meanwhile, in recent months, the inflation rate has also been rising. Contrary to the design and intention of the Thatcher government's plan, private business has been suffering severe damage while the least efficient of the nationalized industries survive serenely.

France's unemployment rate is a lot lower than Britain's. But President Francois Mitterrand calls jobs the "priority of priorities" and is beginning to draw the smaller European countries into a coalition to push for more jobs. France's inflation rate is already high, but a newly elected Socialist government can hardly join Britain and Germany in the campaign for discipline and fiscal restraint at all costs. The French pressure for reflation now adds another internal strain to the Common Market.

In the United States, the Reagan administration has given a good deal more attention to its budget than to its foreign policy. The same process, for similar reasons, has gone even further in Europe. The Atlantic countries seem to have entered a period in which governments worry, first of all, about domestic economies and their effects on domestic politics.