Final answer:
Hernan Cortes burned his ships to prevent his troops from returning to Europe and to commit them to their mission in the New World.
Step-by-step explanation:
To prevent his troops from returning to Europe, Hernan Cortes decided on a drastic measure to ensure the commitment of his men to their mission in the New World. He burned his ships, an act that symbolized that there was no turning back, effectively committing his expedition to either succeeding in their conquest or perishing in the attempt. This decisive action was part of Cortes's campaign against the Aztec Empire and played a key role in ensuring that his troops were fully vested in the efforts to conquer and claim the lands for Spain.