| How They Joined | Countries | Extra Info |
| After the Attack on Pearl Harbor | |
| After the German Invasion of Poland | |
| After the German Invasion of Poland | |
| After the Attack on Pearl Harbor | |
| After the Invasion of the USSR | |
| After the German Invasion of Poland | |
| After the Phoney War | |
| After the German Invasion of Poland | |
| After the Phoney War | |
| After the Declaration by the United Nations | |
| After the Declaration by the United Nations | |
| After the Invasion of the USSR | |
| After D-Day | |
| After D-Day | |
| After the Declaration by the United Nations | |
| After the Attack on Pearl Harbor | |
| After the Attack on Pearl Harbor | |
| After the Attack on Pearl Harbor | |
| After the German Invasion of Poland | |
| After the Attack on Pearl Harbor | |
| After D-Day | |
| After D-Day | |
| After the Attack on Pearl Harbor | |
| After the Declaration by the United Nations | |
| After the Attack on Pearl Harbor | |
| After the Attack on Pearl Harbor | |
| After the Attack on Pearl Harbor | |