The Clinton administration tacitly approved the transfer of arms from Iran and helped in turning Bosnia into an Islamic militant base, Jatras said, adding that Washington later gave preference to the aid from Saudi Arabia, finding Riyadh's influence in Bosnia "healthier" than Iran's.
Jatras, now a partner in the Venable law firm in Washington, was a Republican Party foreign policy analyst in the Senate from 1975 to 2002. As a specialist for Eastern Europe, he compiled five reports on Yugoslavia in the 1990s.
Jatras was examined in the courtroom by Steven Kay, Milosevic's court-appointed defence counsel.
The witness, citing his 1997 report called "The Green Light for Iran", said that the Clinton administration had signalled to the Croatian government to leave open channels for Iranian arms.
While in 1992 and 1993 most of the weapons for the Bosnian army arrived from Iran, as of 1994 the Clinton administration preferred another network from Saudi Arabia which today would be called al-Qaida, he said.
Quoting a statement by a Saudi official from the Washington Post of 1996, that weapons worth 300 million dollars had been delivered to Bosnia-Herzegovina, the witness said that the US had disregarded long-term consequences at the time.
Jatras said that foundations for a global terrorist network, with Osama bin Laden at its centre, had been laid in Bosnia and Kosovo.