The most obvious one is economic - before this war started, oil was flowing freely. After this war started, oil flows are threatened and prices are rising. Europe is both more economically and more politically vulnerable to these price spikes than the US is
Sounds like a good reason to escort tankers through the Strait of Hormuz.
They've also annoyed Europe with the whole Greenland thing.
Trump wants Greenland because he thinks that the US can’t trust military agreements with Europe. You proved him right when you refused to let us use your bases to launch attacks on Iran despite us having an agreement to let us do that.
Hesitation to allow the use of bases was likely due to a concern of entanglement; Europeans don't want to be drawn into a war they don't need when there is a war ongoing in Europe (Ukraine) against a more important threat (Russia).
It’s going to cost you Greenland. Also, it’s not like you respect their sovereignty either; Greenlanders want to be independent, not a colony of Denmark.
There seems to be some cognitive dissonance taking place in some people's heads here. On the one hand, Europe is useless and we don't need their help. On the other, we actually do want their help but Europe is being selfish.
There is no dissonance. We don’t need your help and we think you’re ungrateful retarded weaklings for not being willing to defend your own shipping lanes.
But then when America pursues its interests (Iran) and Europe pursues its interests (Ukraine), now suddenly we need the old alliance back in action and if America goes to war with some random sand people country, Europe needs to go with them, otherwise they are "bad allies". Even though separate strategic focuses for each half of the alliance was America's idea.
What separate focuses? The US paid for all of Ukraine’s weapons. Without American assistance, Russia would have taken the country in three days. If Europe was as generous as the US was, they’d be paying for every bomb and missile used against Iran.
Lastly, two further relevant details - Europe has large numbers of citizens living in the Gulf states. The UK alone has over 300,000 expats living there. It does cause a headache for them when said expats start getting bombed because a war has broken out.
Sounds like another good reason to get involved, though the UK government hates their citizens in Dubai and views them as tax cheats.
There are also concerns surrounding international law. I know international law as a concept has become a bit of a joke, but European countries remain wedded to the idea because, as smaller states, they benefit from a rules-based system existing. So if any country, be it Russia or America, undermines that concept, it can make them nervous.
If a rules-based order is so important to them, then they should have not broken the rules by, amongst other things, rigging elections, crafting protectionist “safety” regulations, and writing bills of attainder to steal money from tech companies.
Europe has been willing to help in some ways as the conflict has grown. When Iran decided to chimp out and fire missiles at everyone around them, including UK sovereign bases on Cyprus via their proxy Hezbollah, Europe sent warships, fighter jets, AA systems and technical personnel to help with the air defence operation in the Gulf. They have since shot down many Iranian drones and missiles. This helps the US since it frees up their own resources to focus on striking targets in Iran.
That doesn’t help the US at all. It helps Europe by not being bombed. The alternative isn’t the US dispatching a ship to protect you, it’s letting you get hit. You’re bragging about your military defending its territory, the bare minimum necessary to be a sovereign country.
As a person from a European country I can say there are real, strategic reasons stemming from national interests for why European countries would not want to join in with bombing Iran.
No one is asking you to bomb Iran. Trump only asked you to help escort tankers carrying oil to your own ports.