IT SAYS SOMETHING not altogether comforting about the Atlantic Alliance that it took Washington and its allies four weeks to make their first common statement on Poland. The statement, however, issued by NATO foreign ministers yesterday, is not bad. It puts responsibility on the Kremlin as well as on the Polish regime. It makes three demands--the ending of martial law, the release of prisoners, the restoration of an internal Polish dialogue--that are hardly unreasonable. It underlines the Polish regime's economic desperation by making formal the existing ban on new non-food commercial credits and by suspending negotiations on Poland's foreign debt. It warns of sanctions against Moscow that the allies might yet impose on their own.

There is nothing surprising here and nothing likely to bring an abrupt turnaround in Warsaw or Moscow. Still, though the alliance continues to deal with several hands, it is now speaking with one voice. How unfortunate, then, that an asterisk must be added. Greece sat out key parts of the NATO declaration, the new socialist government choosing in effect to give aid and comfort to the crushing of the workers in Poland, the better to press its grievance against fellow NATO member Turkey--it imagines.

In the NATO declaration, the most sensitive element is the suspension of negotiations on rescheduling Poland's repayment of the $10 billion in principal and interest due Western governments and banks in 1982. A game of high-stakes, international "chicken" is under way. The Poles, with immense debts and no way of their own to pay, threaten that if their Western creditors press them too hard they will default and do grievous damage to the international banking system. The creditors, with governments among them leaning on banks among them, hint--there is not the consensus yet for a real threat --that the whole East bloc's access to credit will close 1)if Warsaw or Moscow does not pay up and 2)if Poland does not return to renewal and reform.

It is easier for Americans, owed little by Poland, than, say, Germans, owed a lot, to demand that Poland be forced to the wall. But since Americans and Germans are not only allies but also members of the same banking system, it is worth a strenuous effort to establish a common policy on the debt. There will be time to argue over whether the creditors should have allowed themselves to become so precariously exposed. Now is the time to seek agreement on how to make the debt work as a lever on Poland, not on the West.