Styjun

I know we've come to expect unusual behavior from the present POTUS, but I really fail to understand the benefit for the US of recognizing Israel as owning the Golan Heights.

For one thing, it overturns the general post-war consensus that nations can't increase their territory through military action. And, well, it doesn't seem like it will do anything except isolate the US diplomatically.

This question shouldn't be construed in any way, shape or form as support for Assad's government. Or a strong desire to force Israel's hand to return it without security assurances from Syria.

This is the full text of the tweet.

After 52 years it is time for the United States to fully recognize Israel’s Sovereignty over the Golan Heights, which is of critical strategic and security importance to the State of Israel and Regional Stability!

–Donald Trump, via Twitter (2019-03-21)

Edit: apologies to both answers given so far, but I'd like to shift the discussion away from the electoral motivations to what concrete benefits the US could expect if this policy was actually implemented. I.e. how is this good "for the US", rather than any political parties.

I'm not sure there is much benefit to the United States. It won't increase Israel's reliablity as a military ally or trading partner, since they already filled these roles without any US recognition of their possession of the Golan Heights. As the question noted, it will likely only score negative foreign policy points.

However, it's not the US in some amorphous sense that's taking these actions, but the US President, Donald Trump. It's not at all unusual for a president to take actions that aren't to the overall benefit of their country for personal reasons. Consider Richard Nixon, spying on his political opponents out of paranoia. Or Nicolas Maduro, engaging in deficit spending to boost his re-election chances in 2013. For that matter, consider the policy of Trump himself toward Venezuela, which is unlikely to bring much benefit to Americans, but is intended to provide a rhetorical point about socialism in the 2020 elections.

And there are several ways this recognition of the Golan Heights could benefit Donald Trump.

1. 
   

   Trump is making a play for Jewish voters. He hasn't exactly been subtle about it.

   
   
   

   
   

   The ‘Jexodus’ movement encourages Jewish people to leave the Democrat
   Party,” he tweeted. “Total disrespect! Republicans are waiting with
   open arms. Remember Jerusalem (U.S. Embassy) and the horrible Iran
   Nuclear Deal!

   
   

   
   
   

   Since Jewish voters are more likely to be "pro-Israel" in a broad sense, actions that seem to favor Israel may increases Trump's standing among this demographic. If Trump sees recognizing Jerusalem as the capital of Israel as an action that will help bring Jewish voters to his side, it's easy to see why he'd think the same about recognizing its possession of the Golan heights.

   
   



2. Right-leaning people tend to be more supportive of the actions of Israel's government in general. Whatever Trump himself thinks, appearing to stand by Israel may increase the solidity of his support among his core base, For reasons why right-wing people might be more supportive of Israel, see the answers to this question.




3. Trump himself is fairly hostile to Muslim people, as has been extensively documented. It is possible that this might motivate him to be unsympathetic to Muslim countries' land claims.

As for the concerns that you mention, they aren't as important as one might think. Trump doesn't care much for international consensus or diplomatic isolation. He's made remarks that have been hostile to the traditional allies of the US, and drawn nearer to some traditional adversaries. I doubt diplomatic isolation is a major concern for him.

This could also be a way to boost Netanyahu's chances in the upcoming Israeli elections which he's projected to lose. A claim over the Golan backed by the U.S goes a long way into shoring public sentiment in Israel.

The same question can be asked vis a vis the recognition of Jerusalem as Israel's capital. The move displaced decades of U.S foreign policy and ultimately appears to have done a lot of harm to the U.S' standing internationally. So if the U.S isn't gaining from such moves, why is the Trump administration undertaking them?

For one, Trump does not have a lot of allies. Which makes the necessity of supporting powerful political groups like AIPAC paramount. By dislodging decades of foreign policy, Trump is able to gain the support of powerful political groups and their constituencies.

Also, the Pentagon requested a 110% increase in the funding that supports the ongoing occupations of Iraq, Syria and Afghanistan. The conditions for all out war are being put in place should Israel and Hezbollah engage in another conflict. Because realistically and in my opinion, Levantines(Lebanese, Syrians and Palestinians) would never acquiesce such a capitulation and this, in essence, is another move to create the conditions for escalation in the region. As to how escalation is beneficial to the U.S? The purported elimination of Hezbollah -following an attack on the Golan(something that happens intermitently) which the U.S now considers Israeli territory- would be classified as beneficial to the U.S and its allies.

It seems to be a staple of Trump's negotiating strategy. He offers "X" for a property. When the offer is rejected he walks away. Should the seller later come to him and ask for the "X" already offered he counters with less than "X". And should the seller reject the offer and come back Trump offers less than before. The seller knows he needs to act now or the next time he will get even less.

Now, let's look at the Israeli-Palestinian conflict. The Palestinians now say they want the 1967 borders. They could have accomplished that in 1967 but the Arab states promoted the Three No's.

Since then Jerusalem, the West Bank settlements and the Golan Heights were part of their negotiating strategy. Now, with the US Embassy being in Jerusalem it's crystal clear that Jerusalem will be the Israeli capital. (The Palestinians may yet get a piece of it - but they better hurry to the negotiating table.) Likewise for the Golan Heights. If the Palestinians and Syria don't negotiate a real peace now the Golan Heights are gone as a negotiating stick.

There will be no organized violence over this in the middle east. Sunni's care about Jerusalem and outside of a few weeks of ineffective protests nothing happened. The Saudi, Egyptian and Jordanian governments couldn't care less about the Golan Heights. And, since Syria is now completely within the Iranian sphere (I wouldn't call it a puppet state) they really don't care what happens. In fact there may even be a secret glee about it.

So, what is the end result? Should the Palestinians and their supporters want peace with Israel they need to act now because they're losing their bargaining chips.

There is no befit to US. Aside from that US considers Israel and ally.

Having those height makes Israel defense easier.