People throw Molotov cocktails and stones at Soviet Army tanks in front of Czechoslovak Radio station building in central Prague during the first day of Soviet-led invasion to then Czechoslovakia August 21, 1968. AP – In this Aug. 21,1968 file picture, Prague residents carrying a Czechoslovakian flag and throwing burning torches, attempt to stop a Soviet tank in downtown Prague, Czechoslovakia as the Soviet-led invasion by the Warsaw Pact armies crushed the so-called Prague Spring reforms. In August 2008, the ex-communist country will mark the 40th anniversary of the Prague Spring challenge to Soviet domination – bold pro-democracy reforms that the Kremlin swiftly and brutally crushed. Experts say Russia’s threat of a military response if the U.S. and Czech Republic ratify a missile defense system is mostly bluster. But for Czechs, the timing couldn’t be more jarring. – AP REUTERS/Libor Hajsky (CZECH REPUBLIC) – GF2E45J1BUZ01