Standing before a parade of missile-bearing trucks with signs declaring "Down with the U.S." and "Down with Israel," Iran's loudmouth leader warned yesterday that his country will not be intimidated. "Those [countries] who assume that decaying methods such as psychological war, political propaganda and the so-called economic sanctions would work and prevent Iran's fast drive toward progress are mistaken," said President Mahmoud Ahmadinejad. His words came just two days before he was to make a controversial speaking appearance at Columbia University ahead of his U.N. General Assembly address Tuesday.