Board Thread:General Discussion/@comment-26210095-20151117214943/@comment-26453572-20151117223503

Yes, but Umbar was said to have been crippled, so if they really were that strong and had that many lands, the War of the Ring would have been no problem for them, and Tolkien would have never mentioned the damage in appendix A. Aragorn told Ecthelion that Umbar's growing might (at the time) would be dangerous if Sauron declared open war. That is why he went to Umbar with his small force, destroyed most of the boats, and killed their captain (who was, at the time, the leader of Umbar). So Umbar might have once contested Gondor, but they were severely weakened both before and during the war, all thanks to Aragorn.