In August–September 1999, Yandarbiyev was assumed as a key figure behind the invasion by the Islamic International Brigade-led coalition of Islamist guerrillas on the neighboring Russian Republic of Dagestan. At the beginning of the Second Chechen War, Yandarbiyev traveled abroad to Afghanistan, Pakistan and the United Arab Emirates and eventually settled in Qatar in 1999, where he sought to obtain Muslim support for the Chechen cause.