The war in Afghanistan was not the main reason the Soviet Union collapsed. Nevertheless, it bankrupted the Soviet state and pointed out the moral blight, skewed priorities and irrelevance of the Communist gerontocracy.
The United States is a vibrant society with a diversified and resilient economy. But it currently stands on the brink of considerable social and economic upheaval, and the Iraq war reveals the fault lines within the world's only superpower. It is a nation living beyond its means by exploiting the status of the dollar as the global reserve currency. The war is costing some $3 billion per week -- all of it borrowed from more productive nations.
The United States is the leader of the free world, which the rest of the world refuses to follow. Even the pathetic "coalition of the willing," a bunch of mostly third-tier nations Washington assembled to back it in Iraq, has crumbled.
Iraq occupies a far more important place in the political debate in the United States than Afghanistan ever did in the Soviet Union. It is divisive, and frustrations on both sides have been exacerbated by the fact that no victory, however defined, can be achieved. Nor can U.S. forces leave without plunging a strategic, oil-rich region into chaos.
http://www.themoscowtimes.com/stories/2007/10/15/007.html