He makes some good arguments. This in particular seems worth keeping in mind:
Many big bad things happen in the world without America, but not a lot of big good things.
We may not like being the sole super power in the world today. And people elsewhere may not like us in that role either. But as our power decreases, the relative influence of other nations becomes greater. Raise your hands who wants to live in a world where China or Russia is the dominant power in the world.
Personally, on the Afghanistan situation I'm undecided. I agree with him that nation building there is not the same as in Iraq. It's a different mix of cultures with fewer people spread over a larger area. That said, whatever we decide I hope we back our decision appropriately. If we're in it, we need to be in it to win it.