Last week Peer Steinbrück, Mrs. Merkel’s finance minister, went even further. Not content with refusing to develop a serious stimulus plan for his own country, he denounced the plans of other European nations. He accused Britain, in particular, of engaging in “crass Keynesianism.”

Germany’s leaders seem to believe that their own economy is in good shape, and in no need of major help. They’re almost certainly wrong about that. The really bad thing, however, isn’t their misjudgment of their own situation; it’s the way Germany’s opposition is preventing a common European approach to the economic crisis.

To understand the problem, think of what would happen if, say, New Jersey were to attempt to boost its economy through tax cuts or public works, without this state-level stimulus being part of a nationwide program. Clearly, much of the stimulus would “leak” away to neighboring states, so that New Jersey would end up with all of the debt while other states got many if not most of the jobs.

Individual European countries are in much the same situation. Any one government acting unilaterally faces the strong possibility that it will run up a lot of debt without creating much domestic employment.

For the European economy as a whole, however, this kind of leakage is much less of a problem: two-thirds of the average European Union member’s imports come from other European nations, so that the continent as a whole is no more import-dependent than the United States. This means that a coordinated stimulus effort, in which each country counts on its neighbors to match its own efforts, would offer much more bang for the euro than individual, uncoordinated efforts.

But you can’t have a coordinated European effort if Europe’s biggest economy not only refuses to go along, but heaps scorn on its neighbors’ attempts to contain the crisis.

Germany’s big Nein won’t last forever. Last week Ifo, a highly respected research institute, warned that Germany will soon be facing its worst economic crisis since the 1940s. If and when this happens, Mrs. Merkel and her ministers will surely reconsider their position.

But in Europe, as in the United States, the issue is time. Across the world, economies are sinking fast, while we wait for someone, anyone, to offer an effective policy response. How much damage will be done before that response finally comes?