Leonid Brezhnev's conservative attitudes yet again chilled relations between the two countries (although they never degenerated to the level of the conflict with Stalin). Yugoslavia backed Czechoslovakia's leader Alexander Dubček during the 1968 Prague Spring and then cultivated a special (albeit incidental) relation with the maverick Romanian President Nicolae Ceaușescu. Titoism was similar to Dubček's socialism with a human face while Ceaușescu attracted sympathies for his refusal to condone (and take part in) the Soviet invasion of Czechoslovakia, which briefly seemed to constitute a casus belli between Romania and the Soviets.