Arbi Alautdinovich Barayev (Chechen: Arbi Alautdinovich Baraev; 27 May 1974 - 22 June 2001) was a Chechen warlord, who in 1996 became the founder and first leader of the Special Purpose Islamic Regiment (SPIR) in Chechnya. Nicknamed The Terminator, Barayev and the SPIR were regarded as one of the main violent criminal organizations operating in Chechnya during the lawless interwar period that followed the 1994-1996 First Chechen War, driving out foreign journalists and humanitarian workers, while undermining the presidency of Aslan Maskhadov during Chechnya's de facto independence until 1999. After the restoration of Russian Federal control, Barayev openly lived in his home village until he was killed on 22 June, 2001.

In August 1999, Russia launched the Second Chechen War in response to the Invasion of Dagestan by the Islamic International Brigade. Dagestan borders Chechnya to the east, and as part of the operation Russian troops entered Chechnya on 1 October to restore federal control over the country, effectively ending its de facto independence. In March 2000, during the early phase of the war, Barayev reportedly betrayed the Chechen field commander Ruslan Gelayev to the Russian military forces, resulting in the massacre of Gelayev's forces in the Battle of Komsomolskoye. According to another version, Barayev and his men merely bribed their way out of Komsomolskoye while leaving Gelayev and his people to their fate. The incident led to the declaration of revenge on the part of Gelayev, whose fighters then blew up several houses belonging to Barayev in his home village of Alkhan-Kala near Grozny, killed a number of his men, and even attempted to assassinate Barayev in Ingushetia. According to federal authorities, more than 40 Chechens died as a result of these clashes.  Chechen surgeon Khassan Baiev, who amputated a portion of the leg of Shamil Basayev after his injury on a minefield, also had operated on Salman Raduyev and Arbi Barayev himself, however Barayev promised to kill him because he would also help wounded Russian soldiers. Baiev described Barayev as "a born killer, and his men were desperados with blood vendettas proclaimed against them for murder. They joined Barayev for protection against the avengers in an endless cycle of violence. ... He owned a stable of expensive foreign cars, had several wives, and moved around with an escort of twenty to thirty guards. Everyone assumed that he was in the pay of Russian intelligence. Relatives of Arbi Barayev publicly denounced him for his crimes, saying that the family announced in the courtyard of the mosque that if anyone killed him, they would relinquish all claims. There would be no blood revenge." Facing death threats from Barayev as well as from the federal side, Baiev was eventually forced to seek political asylum in the United States.  Following the Russian occupation of most of Chechnya, Barayev freely lived in Alkhan-Kala and frequently passed through Russian Army checkpoints without any problems, using identity papers of an FSB officer, and was also not included in the lists of people wanted "for participation in illegal armed groups". Once arrested, Barayev was said to be instantly released by the demand of Beslan Gantamirov, then the leading figure in the pro-Moscow government. In May 2000, the Russian military intelligence GRU officer leaked papers about Barayev's affiliation with FSB to a Chechen journalist. In April 2001, Barayev's men allegedly ambushed and killed Viktor Popkov, a Russian dissident working in Chechnya as an aid worker and human rights activist since 1995, in the close vicinity of a military roadblock. According to the United States Department of State, Barayev sent a group of his fighters to train in Taliban-controlled areas of Afghanistan in the spring of the same year. Answer this question using a quote from the following article:

What was his involvement in the war?
In August 1999, Russia launched the Second Chechen War