There's method in Jim Mattis

Secretary of Defense Jim Mattis visited Capitol Hill last week and gave Congress an important message.

He told lawmakers that President Trump had authorized him to decide how many American military personnel should be deployed in Afghanistan. This is good news if there is to be anything like a sustainable peace there.

For too long, the military has been unable to send more personnel than the amounts decided arbitrarily by President Obama, who was obsessed with building a legacy as a peacemaker rather than with doing what would have been effective. This forced the Pentagon to keep a low troop presence in Afghanistan, but it was not a path to stability, let alone peace. The caps were akin to Obama's declaration that the Iraq War was over, when all that was over was Washington's commitment to the benighted people of that country.

Obama's approach was the height of strategic incompetence. Elevating domestic politics over strategic needs, he prevented the military from carrying out his own strategy and attaining his own goals.

But where Obama was strategically illiterate, Mattis is the opposite. A keen thinker renowned for his grasp of military theory, history, and philosophy, Mattis can bring new energy to America's long war in Afghanistan. His strategy, due to be presented to Congress next month, is likely to involve three key components: combating Islamic State, strengthening the Afghan government, and pressing the Taliban and other insurgents toward serious negotiations.