sentences:  The War of Dagestan was used as a "casus belli" to trigger the Second Chechen War, when Russian federal troops entered Chechnya and ended its independence.By June 2000, the war had entered an "insurgency phase", where Russian troops would perform several day-long "zachistka" () operations in Chechen villages.On 22 June 2001, Russian troops launched a "zachistka" on Alkhan-Kala, a large village south-west of Grozny, triggering an armed clash with Chechen separatists.