After the Soviet Union withdrew, the world's interest in Afghanistan flagged. When the Najibullah government didn't collapse, the international community did not have the wherewithal to deal with Afghanistan, plot its future, find sustainable leaders. World events quickly overshadowed Afghanistan. By the end of 1989, just months after the Soviet withdrawal, the Berlin Wall came crashing down, Reagan declared communism defeated, and the Soviet Union began to disintegrate. Afghanistan was yesterday's war. The wider world had done the most dangerous of things. It had stuffed this tiny country with massive amounts of weapons, including the precious Stingers, had turned over the countryside to the volatile discordant mix of mujahedeen factions, and then had walked away. For the United States, the war it was really interested in had been won; the proxy war was of little interest. The mujahedeen were the victors, the Communists were the losers. It didn't matter that the mujahedeen leaders had proved themselves to be murderous men who had signed and broken several accords. They vowed to put aside their territorial, ethnic, and religious divides, even traveling to Saudi Arabia to visit Mecca, Islam's holiest site, to seal their promise. But they never kept their promises. And no one cared.SOURCE: I is for Infidel: From Holy War to Holy Terror: 18 Years Inside Afghanistan, by Kathy Gannon (PublicAffairs, 2005), pp. 8-9
Najibullah was forced to negotiate his own removal, and the mujahedeen were eventually given Kabul, despite their bitter rivalries and bloodletting. The task of negotiating this was handed over to the United Nations. In April 1992, the United Nations fulfilled its mission and Najibullah agreed to step down, despite the fact that there was no coherent alternative government ready to replace him. No sustainable form of a mature government had been cobbled together. No one had even tried. The world had moved on without making even one attempt to find an alternative to the warfaring mujahedeen leaders. The United States wanted to give the spoils of its last Cold War battle to its mujahedeen allies and get out. The world had no interest in carefully assembling a unified government to rule Afghanistan, to rebuild and bring stability. That would have taken sustained involvement, and the forceful removal from the scene of some of the more vicious mujahedeen. Instead, the international community opted for a quick exit.
It was a ludicrous mistake to hand over Kabul to the mujahedeen. It set in motion the chaos that would eventually bring the Taliban to power. But the international community wasn't looking to Afghanistan's future. It wanted out.
And so Afghanistan was handed over to the fractious, feuding mix of tribal warlords, who had been elevated to the status of mujahedeen factional leaders to fight the Soviet Union. Their stature had been enhanced by the billions of dollars and weapons they had received from the United States and the rest of the world.