What IS Israel's capital?

Jerusalem.

Obviously Jerusalem is the capital of Israel.

Jerusalem IS Israel's capital, at least practically speaking. Jerusalem isn't universally recognized as Israel's, though, because of it's rather complicated history and the desire of the Palestinians to make it their own capital as well. Because a lot of nations just don't recognize Jerusalem as Israel's capital and officially consider it "corpus separatam" (a separate body, or its own thing), a lot of people are confused because they're going off that rather than what is actually in place. Obviously, other nations not recognizing it does not change the reality that Israel's head of state and the offices of all its major institutions are seated or at least represented in Jerusalem. For all intents and purposes, you cannot deny Jerusalem's status as Israel's capital.

Now, declaring that he's making it the capital is not what Trump did. He didn't declare Jerusalem to be Israel's capital. What he did instead was essentially admit that we believe that it is, and that the US will recognize that it is with moving the embassy to Jerusalem. Honestly, as far as capitals ago, the only thing that Jerusalem lacks are embassies of foreign nations. That's something you expect to find in capitals, but not something needed to honestly make a city one. In 1995, Congress decided to move the embassy to Jerusalem and through that officially recognize Jerusalem's status as capital but Clinton, with Bush and Obama after him, decided to put a stop to that. All Trump is actually doing is letting the plan put forth by Congress go forth in implementation. Yes, a country and its citizens should be the most important voice in determining what their capital is, and as Israel controls Jerusalem it's fitting that it be considered Israel's. All Trump is essentially doing is recognizing what that choice is, officially.

He's still opening up a large can of worms (or angry snakes as you put it) because the US recognizing it, especially at this time, will cause the Palestinians to be angry and many of them will respond with violence. However, Israel knows that better than anyone, and they're still happy that Trump did what he did for the most part. Our relationship with Israel won't be strained by this, or by much of anything really (they're one of the most pro-US nations on the planet); however, our role in the peace talks with the Palestinians will be put into question because we're no longer pandering to their desire to turn Jerusalem into the Palestinian capital. We will lose some influence with them, at least for some time, and a few other nations that we didn't have the best of relationships with in the Middle East. Tbh, a lot of Arab states say that they oppose it, but their leaders will care less if they're huge US supporters and allies.

Edit: For those saying Tel Aviv, ask yourself what truly makes a capital and figure out what from that list Tel Aviv actually has now. The basic requirements for a city to be a capital city are not met by Tel Aviv, but by Jerusalem as far as Israel goes. Tel Aviv is to New York City as Jerusalem is to Washington D.C., especially considering that the first governments of both nations met in Tel Aviv/NYC and then found more permanent homes elsewhere.

Under Israeli law, Jerusalem is their capital. This is also true in fact, since it is where most of their national government is located (parliament, PM 's residence etc). However, no other country recognizes Jerusalem as the capital and all foreign embassies are located in Tel Aviv. This is because the Palestinians also claim Jerusalem as their eventual capital (specifically East Jerusalem). The ultimate status of Jerusalem is supposed to be determined as part of a peace agreement between the two sides. It's been felt that acknowledging Jerusalem as the Israeli capital would prejudice those proceedings in Israel's favor, thus undermining the process. Trump, for domestic political reasons, decided to officially recognize Jerusalem as the capital.

Jerusalem is Israel's capital and has been for a long time. Other countries have said that Tel Aviv is Israel's capital because they hate Jews and love Islam.

Trump has already undone whatever positive relationships the US had with just about every country in the world - even us Brits, America's bestest ever buddies, are heartily pissed off with him!

For you, and all of your compatriots whose grasp of geography appears to be confined, albeit sketchily, within the borders of the USA, the answer is - Tel Aviv

you could have googled this.

Jerusalem as it always was, is and will be.

The complete Israeli government is already there, though Tel Aviv is considered the Capital per the International Community who have their Embassies there. Israel is a Sovereign Country but is at the mercy of the whims of the Anti-Semitic UN so it is unable to declare the fact that it is Jerusalem.

Tel Aviv

Tel Aviv I think