Doubt that 40,000 would do it. That would bring us up to 100,000 which is about what the Russians had, if memory serves, and that didn’t do it for them. What they lacked in technology they made up for in ferocity, didn’t help. Maybe 500k for ten years might do it. Obama’s between a rock and hard place. And the Habu option is off the table. Obama is damned if he does and damned if he doesn’t. Lesson: don’t make yourself personnally liable for a war, if you can help it. Obama owns it, and it’s the troops who will suffer.