It is a city that straddles the outskirt amongst Israel and the West Bank. It's home to a portion of the holiest destinations in both Judaism and Islam, thus both Israel and Palestine need to make it their capital.
The most effective method to part the city decently stays one of the major issues isolating Israelis and Palestinians. For the initial 20 years of Israel's presence, Jerusalem was separated. Israel calls Jerusalem its unified capital today, however no nations remembers it in that capacity.
UN Security Council Resolution 478 sentences Israel's choice to add East Jerusalem as an infringement of worldwide law and requires a trade off arrangement.