Why are international territorial conflicts difficult to resolve? (4 + sentences)

Because there is no clear mediator or means of cooperation. Often, other nations are forced to simply observe the conflict, because intervention can cause even more problems. Look at the ongoing conflict between Israel and Palestine. So many promises were made by other countries or between the two countries (think of the United Nations, or the failed Balfour Declaration) that haven't been kept, and so the problem is ongoing.