The princes of Greece were bound to help Menelaus get Helen back from Troy primarily because of an oath taken by her suitors. Before Helen married Menelaus, all of her suitors made a solemn vow to support the man she chose in the event of any conflict arising from her choice. This oath was initiated by Odysseus, who proposed that all suitors should promise to defend the chosen husband against any wrongdoers.
When Paris, a Trojan prince,