Brigade was ordered to make a swift push for the centre of the city, but was then virtually destroyed in Chechen ambushes. After finally seizing Grozny amid fierce resistance, Russian troops moved on to other Chechen strongholds. When Chechen militants took hostages in the Budyonnovsk hospital hostage crisis in Stavropol Kray in June 1995, peace looked possible for a time, but the fighting continued. Following this incident, the separatists were referred to as insurgents or terrorists within Russia. Dzhokar Dudayev was assassinated in a Russian airstrike on 21 April 1996, and that summer, a Chechen attack retook Grozny. Alexander Lebed, then Secretary of the Security Council, began talks with the Chechen rebel leader Aslan Maskhadov in August 1996 and signed an agreement on 22/23 August; by the end of that month, the fighting ended. The formal ceasefire was signed in the Dagestani town of Khasavyurt on 31 August 1996, stipulating that a formal agreement on relations between the Chechen Republic of Ichkeria and the Russian federal government need not be signed until late 2001. Writing some years later, Dmitri Trenin and Aleksei Malashenko described the Russian military's performance in Chechniya as "grossly deficient at all levels, from commander-in-chief to the drafted private." The Ground Forces' performance in the First Chechen War has been assessed by a British academic as "appallingly bad". Writing six years later, Michael Orr said "one of the root causes of the Russian failure in 1994–96 was their inability to raise and deploy a properly trained military force." Second Chechen War The Second Chechen War began in August 1999 after Chechen militias invaded neighboring Dagestan, followed quickly in early September by a series of four terrorist bombings across Russia. This prompted Russian military action against the alleged Chechen culprits. In the first Chechen war, the Russians primarily laid waste to an area with artillery and airstrikes before advancing the land forces. Improvements were made in the Ground Forces between 1996 and 1999; when the Second Chechen War started, instead of hastily assembled "composite regiments" dispatched with little or no training, whose members had never seen service together, formations were brought up to strength with replacements, put through preparatory training, and then dispatched. Combat performance improved accordingly, and large-scale opposition was crippled. Most of the prominent past Chechen separatist leaders had died or been killed, including former President Aslan Maskhadov and leading warlord and terrorist attack mastermind Shamil