WASHINGTON — The son of U.N. Secretary General Kofi Annan unleashed a bitter counterattack on investigators of the U.N. oil-for-food program last night, calling probes of the scandal a "witch hunt" that is part of a "broader Republican political agenda." In his first public comments since the scandal erupted, 31-year-old Kojo Annan came out swinging, insisting there is "no substance" to allegations against him and his father. "I feel the whole issue has been a witch hunt from Day 1 as part of a broader Republican political agenda," Annan said in a written statement to CNN. [snip] The younger...