What is the most widely believed though likely false aspect ofthe olympic truce story?

The truce ended all wars.

Explanation:

The Olympic truce is a tradition that originated in Ancient Greece in 776 BC. This tradition states that during the Olympic Games, all fighting during a war must stop, so that athletes and visitors can attend safely. However, many believed that this truce stopped all wars. In fact, the Olympic Games were actually held during both the Persian and the Peloponnesian War.