Not all Jews want Jerusalem as their capital. It's a sacred city to Judaism, Christianity and Islam, and many people from all three religions want it kept as a holy city.
For Muslims, Jerusalem was the first Qibla - the place toward which they turn in prayer. The Islamic teachings state that the angel **riel miraculously took the Prophet from the Sacred Mosque in Mecca to the Furthest Mosque (Al-Aqsa) in Jerusalem. He was then taken up to the heavens to be shown the signs of God. After the Prophet met with previous prophets and led them in prayer, he was then taken back to Mecca.
So you can't see any bad consequences from us (not being a superpower like the US) giving the finger to 1.8 billion people who follow Islam about one of their most sacred religious sites so as to get a few measly votes in a by election? And then giving the finger to Israel by not doing it after that election?
