Following is pulled directly from stockstradr's posting: 

What is the Great Dark Secret of history that Americans are too ignorant to know or too proud to discuss?

Read this excerpt from an interview with Zbigniew Brzezinski, President Jimmy Carter's National Security Adviser:

Q [Interviewer]: When the Soviets justified their intervention by asserting that they intended to fight against a secret involvement of the United States in Afghanistan, people didn't believe them. However, there was a basis of truth. You don't regret anything today?

B[Zbigniew Brzezinski]: Regret what? That secret operation was an excellent idea. It had the effect of drawing the Russians into the Afghan trap and you want me to regret it? The day that the Soviets officially crossed the border, I wrote to President Carter. We now have the opportunity of giving to the USSR its Vietnam War. Indeed, for almost 10 years, Moscow had to carry on a war unsupportable by the government, a conflict that brought about the demoralization and finally the breakup of the Soviet empire.

OK, so what is the Great Dark Secret? THE FACTS 1) Carter, Brzezinski, and others in the administration decided back in July '79 to fund covert CIA involvement in the Afghanistan civil war with the goal to give Russia a Vietnam-like failed war. 2) That conspiracy became wildly "successful" and many historians later concluded it not only gave Russia a Vietnam-like failed war (on a greater scale), but was a pivotal element in the collapse of the entire Soviet Union. 3) Afghanistan was the real victim and "paid" the price to the tune of over ONE MILLION Afghan lives and their country was reduced to rubble, all so that America could give Russia its Vietnam on Afghani soil. 4) America sent countless CIA operatives into Afghanistan during the war, to train Afghanis how to be terrorists against Russians in Afghanistan. America sent millions of dollars in weapons into Afghanistan. What downed the 333 Russian helicopters lost during that war? 

This passage asserts not only did the Carter Administration fund and support a secret war inside Afghanistan, but that the Soviets invaded because of it's existence.  However, Brzezinski is unclear as to whether or not the operations plan existed prior to the Russian invasion.  It would certainly appear to be the case, if the Soviet response was driven by their desire to foil said secret war.

So, which is it?  The timing would seem to indicate we became involved following, as would the phrasing of Brzezinski's letter to President Carter, but the way he describes events contradicts that timing, and make it appear that the Soviets became aware of this secret war and then invaded following.

History tells a different story, especially as regards the Carter Administration's handling of special warfare missions and covert operations.  I mentioned the Desert One debacle because it underscores the point that Carter hamstrung not only our conventional military capabilities, but also gutted our SOF and covert programs as well.  It strains credulity to see his hand behind the anti-Soviet effort in Afghanistan.