It’s the proper procedure - they have a “ranking” how they proceeded with countries that behave like that. The US currently is not quite yet in the “travel warning” area but is getting closer and closer every day (which they, despite the usual secrecy of diplomacy, told the media multiple times).

Considering the huge ramifications a travel warning has, it’s reasonable to go step by step to gradually increase pressure, ideally together with European partners.

The formal travel warning is basically the biggest gun they have in their arsenal.

Amongst others that would mean:

• Most travel insurance providers no longer would cover travellers. This is especially significant for business travel as then individual risk assessment need to be made. (I do the later…it’s not cheap). And companies can no longer require their staff to travel to the US. So huge “risk bonuses” would be required. Even more significant for public employees and the European army personnel currently training in the US.

• Airlines would have to take additional insurance by their brokers to cover flights to and from the US. That can easily double prices for passengers and freight.

• Current trade contracts will have larger insurance costs, industrial goods and equipment that requires maintenance will have issues,etc. This is not a one way street,though,as European staff cannot be trained in the US either. Same goes for science,etc.