signed a letter to Mr Clinton demanding "a full legal and constitutional analysis of the justification of your orders placing members of the United States Armed Forces under the command of foreign United Nations officers".

Senior Republican Congressmen have also introduced legislation to prohibit a president from ordering US troops to wear UN insignia. "A soldier's oath is to the US Constitution, not to the UN Charter," said Tom DeLay, who tabled the motion.

"Forcing soldiers to wear the uniform of the United Nations effectively asks the soldier to serve another power. No American soldier should be put in Michael New's position - forced to choose allegiances between the United States and the United Nations."

In the murky world of peace-keeping, with its deliberately fudged chain of command, such an interpretationwould virtually exclude the US from a future role. With Washington poised to send thousands of troops into the former Yugoslavia, the proposed legislation could deal US diplomacy a devastating blow.

Mr New stood impassively during yesterday's arraignment proceedings near the southern German city of Wurzburg. He did not enter a plea, and there will be a second hearing to set the date of the court-martial, expected to be held in January. The medic, who was described by his commanding officer as a good soldier, does not have much to fear from the trial's outcome.

"We're not going to hang him, or anything like that," a US army source said. His most likely punishment is dishonourable discharge, and a hero's welcome back home in Texas.