Warfighting: Not what it used to be?

I don't mean to be an armed-chair general, but I guess this makes me so. But I was a little surprised to learn that after nine years in Afghanistan, we are only now sending heavy armor, or tanks.

In my day, I think we viewed warfighting a little differently, or at least the doctrines we studied were different. I know times and places change, but certain concepts remain valid, I believe. Otherwise, why would military students still study Clausewitz.

The doctrines I mention here I call the Weinberger-Powell doctrines.

The original Weinberger doctrine, created in 1984 by then Secretary of Defense Caspar Weinberger, stated:

1. The United States should not commit forces to combat unless the vital national interests of the United States or its allies are involved.
2. U.S. troops should only be committed wholeheartedly and with the clear intention of winning. Otherwise, troops should not be committed.
3. U.S. combat troops should be committed only with clearly defined political and military objectives and with the capacity to accomplish those objectives.
4. The relationship between the objectives and the size and composition of the forces committed should be continually reassessed and adjusted if necessary.
5. U.S. troops should not be committed to battle without a "reasonable assurance" of the support of U.S. public opinion and Congress.
6. The commitment of U.S. troops should be considered only as a last resort.

Gen. Colin Powell, as Chairman, Joint Chiefs of Staff, later refined and added to Weinberger's doctrine in the run-up to the first Gulf War as a series of questions that needed to be answered before committing U.S. military forces.

1. Is a vital national security interest threatened?
2. Do we have a clear attainable objective?
3. Have the risks and costs been fully and frankly analyzed?
4. Have all other non-violent policy means been fully exhausted?
5. Is there a plausible exit strategy to avoid endless entanglement?
6. Have the consequences of our action been fully considered?
7. Is the action supported by the American people?
8. Do we have genuine broad international support?

So would someone tell me what doctrine we're using now? Has the Counter-Insurgency manual replaced this. My one big criticism of Rumsfeld is that he did not follow the two doctrines that were formed over 30-plus years of experience.

The fact that after nine years we are just now using heavy armor lets me think something is wrong here, other than the fact we're still there.