(Corrects attribution of quote in paragraph 10 to Mladic)
* Mladic called to testify against will in Karadzic's trial
* Ex-general answers no questions of substance in genocide case
* Mladic denounces court as "satanic"
By Thomas Escritt
THE HAGUE, Jan 28 (Reuters) - Bosnian Serb wartime leaders Radovan Karadzic and Ratko Mladic appeared together for the first time before a U.N. war crimes court on Tuesday and Mladic sidestepped questions from his old ally relating to charges of conspiring to commit genocide.
Mladic, the former general who headed separatist Bosnian Serb forces, and Karadzic, the political leader, are both accused of responsibility for the massacre of 8,000 Muslim men and boys in Srebrenica near the end of Bosnia's 1992-95 war.
Looking frail, Mladic, now 71, was called by Karadzic, 68, to appear against his will as a defence witness in the latter's trial.
The two men are on trial separately, each accused of devising and executing a conspiracy to "ethnically cleanse" Bosnia of its Muslims and Croats to create a pure Serb state following its secession from the former Serbian-led federal Yugoslavia.
"I do not recognise this court. It is a NATO creation. It is a satanic court," said Mladic when asked to take his oath as a defence witness for Karadzic.
But, after being told he risked contempt charges, he asked security to fetch his false teeth and the hearings began.
Bosnia's war, which was part of the bloody disintegration of Yugoslavia, ended in a peace deal hammered out at a U.S. air base in Dayton, Ohio, in 1995 after NATO air strikes that forced Bosnian Serbs to the negotiating table.
Karadzic had a list of six questions he wanted to ask of Mladic, focusing on the general's knowledge of the Srebrenica massacre and the Serb siege of the capital Sarajevo, and how much of that information he had passed to Karadzic.
Karadzic was expected to argue that the two had no common plan and that he was unaware of his most senior general's activities, and so could not be held personally responsible for the worst bloodshed in Europe since World War Two.
Mladic gave the same response in answer to each question: "I cannot and do not wish to testify ... because it would impair my health and prejudice my own case," he said, offering instead to read a seven-page statement he said he had written the previous evening - an offer judges refused.
Proceedings were complete after less than two hours and Mladic was led out, exchanging nods with Karadzic.
"Thanks a lot, Radovan. I'm sorry, these idiots wouldn't let me speak. They defend NATO," he said as he passed, gesticulating to the public gallery, separated from the high-security courtroom by a bullet-proof pain of glass.
Beforehand, his lawyer Branko Lukic had told judges that Mladic's poor health, the result of a series of strokes that left him partially paralysed, had caused gaps in his memory so that he was unable to distinguish fact from fiction.
Both men were indicted shortly before the end of Bosnia's war, which cost up to 100,000 lives, but spent more than a decade living on the run in Serbia before their arrest.
They face sentences of up to life imprisonment if convicted of charges that include crimes against humanity and genocide. $1 = 0.7313 euros) (Editing by Anthony Deutsch and Mark Heinrich)