I mean what’s there to say but, well…FAFO.
Obviously Iran will be using their newfound leverage to force policy changes in the EU first. That will be very, very bad.
(and if I can say something really unpopular: this is why Trump wants and asks for EU and other allies to support the US in this war. Not because it's just or fair ... nothing to do with it. More like "deal with Trump or deal with mullahs", expecting any sane person to choose Trump, rather than deal with the consequences of Iran either taxing Hormuz or acquiring nuclear weapons)
Also, Trump asking the EU and other allies to contribute seems much more to be about shifting blame and cost. Participating in the quagmire he created, with such an unreliable partner seems like a terrible idea.
That means that for Europe to trade with Asia, it has to either pay tax to 10 different countries ... or to the US.
In other words, it gives the US the ability to apply import tariffs the way the UK famously did: if France or any EU country wants to trade with China, or any Asian country they'll have to pay tariffs ... to the US. The American revolution coming full circle.
Obviously words cannot describe what a disaster this would be for the EU.
Here's how politico describes the EU's relation with the Iranian regime in one article: "Iran continues to hold and execute European Union citizens, using capital punishment for accused spies or dissidents, leading to severe diplomatic tension and EU condemnation of 'hostage diplomacy'"
You think Trump is untrustworthy? When is the last time Trump invited someone for diplomacy ... then had that person executed?
I mean, I get why people make the point that Trump is the worst US president ever to deal with. That's politics, and there's an election coming up... what I don't understand is why people get confused about that still making him 1000x better than a lot of other parties.
You answered your own question - that’s politics. It doesn’t need to make sense to you.
When Trump approved Israel's strike on the Hamas negotiators...
The geopolitical reality is US gets disproportionately fucked if OPEC+ doesn't have to care about US regional US security umbrella leverage... forced to cooperate with Iran, GCC countries and Iran can price US shale out of export market while saving 100s of billions per year on not buying US services/hardware (which potentially drops their fiscal breakeven per barrel below US shale). Iran can increase toll 500%, i.e. $50 barrel + $5 Iran tip and every sane global actor would still choose MENA oil who can push prices and supplies that bankrupt US+VZ+CA oil network, if only out of cathartic lulz.
This is the real strategic dilemma, US protection racket leverage is what incentivizes GCC producers to price barrels that allow US shale to survive, and recycle 100s of billions of petro dollar into US hardware and services. If US unable protect i.e. US doesn't have capabilities to prevent Iran from glass GCC infra and US doesn't have capacities to survive forward basing as security provider, then that leverage gone. Now obviously US won't let shale go bankrupt, but CONUS energy would simply become another subsidy/burden item.