Post WWII Military Involvement Crossword

The event that caused America to join WWII (2 words).
The first Japanese city to be nuked.
The second Japanese city to be nuked.
The battle that cause America to go on the offensive against Japan.
The area that Japan took from the US soon after the US joined WWII.
The substance used when firebombing Japan.
A system where cargo ships would be escorted across the Atlantic by warships.
The battle where Japan attempted to cut off US supplies (2 words).
The battle where the US invaded Normandy Beach (no hyphen).
The location of largest naval battle in History (2 words).
A meeting where the Soviet Union agreed to attack Germany at the same time the US attacked France (2 words).
The set of trials after WWII involving the incrimination of those who caused WWII and the holocaust (2 words).
The group created after WWII to prevent a future world war (2 words).
The battle where Germany attempted to take a major supplier for the Soviet Union.
The battle named after the motion of the German defense line (2 words).
After FDR died of a stroke, who took his place (2 words).
The code name for the US' efforts to create a working atomic bomb in WWII (2 words).
The famous battle where the US attempted to capture an island close to Japan for the B29 Bombers (2 words).