ROME—Just when you thought it was safe to book a flight to Europe for a long-awaited summer holiday, things are getting complicated again. Last summer, Europe (with the exception of Croatia), not only missed out on American and Asian dollars, but they also spent much of the tourism season duking it out with each other over changing restrictions and a complicated color code, fed by what was the beginning of a deadly second wave that has only subsided thanks to vaccines. This summer was supposed to be different with Brussels promising to open up the borders by high summer. That's not exactly how it is happening. But this time it isn't so much about COVID surges and variants. It's about European leaders’ pettiness and tit-for-tat attitude.

Thursday, the European Union seemed to backtrack on a promise to open up the 27-member state to Americans by mid-June, instead doubling down on restrictions on non-essential travel from the U.S. and U.K (while still allowing individual countries to set their own rules). Some countries like Greece have been open to tourists since May and others, like Spain and France, had already announced welcoming Americans by June 9. And the travel ban extension apparently won’t apply to Italy’s COVID-tested flights with some U.S. states through Alitalia and Delta. When posed the question about these countries that are defying the ban, a spokesperson for the EU said simply, “It’s complicated.”

All this means that with the exceptions of a country like Greece, which made clear in late spring that it would be completely open, most European countries are going to lose out on American tourism for the whole summer and thanks to changing rules, they are missing out on a lot of European tourist dollars, too. Even if restrictions are lifted, Americans have already made their summer plans.

A diplomat who was involved in the talks hinted that the extension of restrictions is based on an impasse between the Biden administration and the EU on when America will finally welcome Europeans. As of now, that is apparently not in the cards. The U.S. does not need European travelers the same way Europe needs Americans, so it is unclear if playing hardball is going to pay off. Travel is still restricted between the U.S. and Canada, for example, based on a similar impasse.

Europeans who had hoped to travel abroad won't even find it easy to travel within the EU. France threw a curveball at the U.K. in late May, banning all travel by Britons to the country except for the most “compelling reasons” despite France having almost eight times as many daily cases as the UK. And they are strict about it, too. If you say you are going to Paris for a funeral, you had better produce a death certificate and in the age of Zoom, even work doesn’t count.

Germany and Austria were the first to impose a similar ban on Brits after the Delta variant first identified in India became dominant in the U.K. Spain and Portugal, on the other hand, have lifted all restrictions for Brits traveling there.

The UK, using what it refers to as a “stoplight” approach to travel, will move Portugal from the green light list to amber on June 8, meaning anyone on holiday there after that date will have to quarantine upon return, a devastating blow as Brits are a major driver of tourism. Italy, Greece, and Spain are also considered amber, making travel less appealing. Portugal had been the only traditional sun holiday destination on the green list. Now Brits will have to spend another summer on their own beaches. Singapore, Australia, and New Zealand are all green-lit for British travel, but none of those countries allow anyone from the U.K. in, making the whole system counterintuitive without reciprocity. Plus, even being on the U.K.’s green list still requires testing which often adds hundreds of dollars to a trip.

France also instituted a similar color-code system on Friday, making certifiable vaccination compulsory for anyone traveling from a country dubbed “orange” like the U.S. Unvaccinated travelers are not allowed entry, even with a negative test. It is unclear how France intends to certify vaccinations, and if they will recognize those not used in the EU.

The fluctuating system makes it difficult for holidaymakers to plan, but the real added headache this summer is how European countries have different testing requirements and capabilities. Many countries require a PCR or molecular test between 48 and 72 hours of departure, but few countries deliver them within 24 hours, making planning difficult—especially when you have to find a lab in a foreign country to return home. The tests run anywhere from $50 in Italy to $200 in Holland and have to be done on both sides of the trip, making the tests often more costly than airline tickets, which are attractively low on Europe’s low-budget carriers.

The EU has said it will consider allowing vaccinated travelers entry, even from countries like the U.S., but they have yet to allow Americans access to the green passport program with proof of vaccination at least 14 days before arrival, which will be the standard in Europe by July 1. EU commissioner Didier Reynders told CNN that vaccinated Americans could come to Europe, but they would likely have to apply to the destination country’s health system to have their vaccination validated, or risk having to quarantine.

Europe has struggled with a unified approach to the pandemic since it began, with many tourist-starved countries like Italy, Greece, and Spain jumping the gun and allowing non-EU travelers in before the bloc had come up with a unified approach. Schengen restrictions mean that people can move freely by land between countries, making it hard for individual nations to enforce restrictions. And with Germany, Austria, and France banning Brits, and the UK making travel to anywhere in Europe difficult, many people will be stuck spending yet another summer at home. And for Americans eyeing a little European culture, this likely won't be the year to get it.

And as tourism business owners in Portugal learned this week, the rules can change swiftly.