I don't think it's sticking his nose in where it doesn't belong. He's not sending troops. He didn't decide that Jerusalem is now Israel's capital city. The only thing he did was agree with the decision Israel made years ago, in 1980. The US Congress even agreed with Israel, and voted that way in 1995.
Political pundits will argue about his words, but that's all they are. Since the Arabs couldn't care less what the US says, what difference will it make?
They say that by "siding" with Israel, the US is stirring up trouble. I ask you, on your time on earth, even not paying that much attention to the ME, are you aware of any time where it's been peaceful there? Did peace talks ever work? Has the UN ever managed to ease tensions? Have Russia, the US or any other country made a difference there? No, nothing has changed.
What should the world do? Keep working towards peace there? Sure, but there has to be a tiny bit of will to want to end the violence. Any reason to kill or blow something up and there is always someone ready with a gun or some explosives.
There has to be a will to stop. That hasn't happened yet. They still want to fight and destroy each other.
A poor analogy perhaps, but former smokers can only say that they have quit when they are standing in a warehouse full of cigarettes and people lighting up, but not do it themselves. There has to be a will to quit.
Having spent some time there, in my limited experience, there is a lot of hate floating around. Hate for Jews. Hate for the US. Hate for Christians. Hate for Russians. Hate for Muslims. Hate for other ME countries. Hate for the UN. etc. What can you do?
Trump agreeing with Israel about Jerusalem will be used as an excuse to keep the bad times rolling. Claiming that he's adding to the tensions there is silly. It's never stopped.