A secretive plan to sell tanks to Saudia Arabia has caused a furor within Germany's governing coalition, members of which are demanding an explanation. The deal, which violates a tradition of avoiding weapons sales in conflict areas, signals a fundamental shift in German arms trade. Is Chancellor Angela Merkel's foreign policy still credible?

Guido Westerwelle is used to adversity. For years the German foreign minister has ranked low in opinion polls, his policies raising eyebrows even among fellow party members. Westerwelle has fought just to stay in office for the rest of this legislative period, but since last Tuesday, even these chances of this have dwindled.

That day Westerwelle, a member of the business-friendly Free Democratic Party (FDP), paid a visit to their parliamentary foreign policy working group. It should have been a meeting of friends, but the atmosphere was anything but friendly. These members of the Bundestag, Germany's parliament, had learned that the Federal Security Council had approved the sale of more than 200 model 2A7+Leopard tanks to Saudi Arabia.

The FDP politicians wanted answers. Rainer Stinner, the party's foreign policy spokesman in parliament, addressed Westerwelle directly. The Security Council must have very good reasons for selling tanks to a country such as Saudi Arabia, Stinner said, and he'd like to hear those reasons.

But the foreign minister declined to disclose any information. Federal Security Council meetings are confidential, Westerwelle demurred. The foreign minister then offered a brief presentation of his position on the political situation in the Middle East before lapsing into a rather telling silence.