The effects of "glasnost" on political criticism and discussion in the Soviet Union further strained the Cuban-Soviet alliance. After Castro bashed "glasnost" during a joint Soviet-Cuban conference in Havana in 1988, the Soviet elite became more critical of Soviet foreign policy towards Cuba, and critical articles in Soviet newspapers soon emerged. Although Havana could not afford to upset Moscow, its main ally, Castro in February 1989 led a small expulsion of Soviet diplomats at the Soviet embassy and banned the sale of Soviet publications and news outlets, He stated, "We could not hesitate to prevent the circulation of Soviet publications in Cuba."