Would YOU Assassinate Hitler?

Suppose you were in a Bonhoeffer type situation. Suppose it were revealed to you that a certain person was going to develop a weapon of mass destruction and use it to kill one billion innocent people. Suppose you were suddenly placed before this person with a gun in your hand. You know that if you assassinate this person, the weapon technology will never be developed and those one billion people will never be killed. WHAT DO YOU DO? Do you commit murder and suffer whatever the moral consequences of your act with the thought that "the end justifies the means", OR, so you refrain from playing God and taking the law into your own hands on the grounds that you become just as bad as the person you assassinate? Tough choice for anyone. I can tell you what Dr. Who (Tom Baker) decided with regard to the Daleks. But what does YOU decide to do, based upon YOUR values and beliefs?

Next, tell me how Mohandas Gandhi would have handled the situation and what his reasoning would have been.