Jerusalem is a holy site for Jews, Muslims, and Christians. Israelis and Palestinians both lay claim to it as their capital. Jerusalem is the most sensitive of all the issues that need to be addressed in order to achieve a peace agreement between Israelis and Palestinians. But Donald Trump determined an important aspect of the United States' position towards Jerusalem before any agreement. Most of the rest of the world feels that it ought not to be dealt with first, that it ought not to be dealt with separately, and that it ought not to be dealt with unilaterally.