|and countries should not be allowed to gain territory by military force>>|
You live on the Moon? What country (USA) including did not establish its final frontiers by force?
The territorial Dispute however is with not a country-There was never a Palestinian State, but about establishing a country-(a potentially very hostile country) that must take into account Israel's interests (really prerequisite to even considering this possibility)
The union of Texas with the United States of America and the ambition of that country to take control of Mexican territory, led to the war with the United States of America. Although the Nueces River marked the border with Texas, after joining the United States of America, the Texans claimed that their border stretched down as far as the Bravo or Grande River which lay further south. Mexico protested, but the Texans occupied the land between the two rivers. There were conflicts between Mexicans and U.S. citizens, and the United States of America used this as an excuse to declare war on Mexico.