In 1928, Stalin declared that class war between the proletariat and their enemies would intensify as socialism developed. He warned of a "danger from the right", including in the Communist Party itself. The first major show trial in the USSR was the Shakhty Trial of 1928, in which several middle-class "industrial specialists" were convicted of sabotage. From 1929 to 1930, further show trials were held to intimidate opposition: these included the Industrial Party Trial, Menshevik Trial, and Metro-Vickers Trial. Aware that the ethnic Russian majority may have concerns about being ruled by a Georgian, he promoted ethnic Russians throughout the state hierarchy and made the Russian language compulsory throughout schools and offices, albeit to be used in tandem with local languages in areas with non-Russian majorities. Nationalist sentiment among ethnic minorities was suppressed. Conservative social policies were promoted to enhance social discipline and boost population growth; this included a focus on strong family units and motherhood, re-criminalisation of homosexuality, restrictions placed on abortion and divorce, and abolition of the "Zhenotdel" women's department.