A lot more work than many realize went into recruiting, paying, and training Liberia's new professional army. Here are a few lessons learned from Liberia that might help in Afghanistan:

It might be necessary to start over. Security forces that are distrusted and feared by the population can be worse than no security at all. Disband corrupt units completely and invite soldiers or policemen to reapply individually so that they can be vetted. Also, ensure the public is involved in the vetting to help re-establish the force's credibility.

All institutions must rise together. It is dangerous to raise a capable army that the Finance Ministry cannot pay. This is a coup d'état in the waiting.

Modern warfare is more than shooting. Incorporate literacy and respect for the rule of law and human rights directly into basic training. Also, take every training opportunity to imbue a sense of national identity into the force to overcome parochial tribal allegiances, and don't let any one ethnic group dominate the ranks.

Don't create a force so strong it provokes the neighbors to build up their own militaries in response. In Afghanistan and Liberia, the AK-47 is the weapon of mass destruction, and arms races often lead to bloodshed.

Lastly, as foreigners, be humble. Afghanistan and Liberia are worlds away from the United States, yet the country still creates "mini-me" versions of the U.S. military and police abroad. Throw away the American playbook and think creatively, in partnership with Afghans, about what is truly needed to defend them from their threats. It won't look like Fort Bragg.