Speculation, Bustle, and Training Teammates

The first problem was that the missile wasn't big. It was probably just a tactical nuclear missile, but even if it was, it could only have come from the American government.

It was almost impossible for other forces to launch a tactical missile in Manhattan.

It was much easier to detonate a nuclear bomb.

But if he used this weapon in New York, even if he defeated the Chitauri, how could things be any better?

This might mean that the battle situation had deteriorated to an uncontrollable level, which was why Batman had grabbed the nuclear weapon and was prepared to die with the enemy's command center.

Luke pondered this for a long time, but deemed it unlikely.

Executing nuclear weapons in any country was a decision that had to be made with great caution. It was difficult to launch them quickly, unless you were prepared to blow up the ground and have both sides perish together.