Every day, €4.5 billion ($4.9 billion) worth of goods and services cross the Atlantic between the European Union and the United States.
This bilateral trade is the largest in the world.
The tariffs imposed by the Trump administration now make doing business in the US more costly for Europe — and Brussels is preparing to respond strongly.
Nevertheless, the preferred option in the EU is a negotiated solution with Washington.
Germany's finance minister, Jörg Kukies, is even calling for removing all tariffs on all imports:
"The easiest way to assure balance and fairness is if everyone goes to zero and then we have free trade, efficiency, and economies of scale. The key is to send the signal that we are willing to include reducing tariffs all the way to zero," he said.
Zero tariffs?
Trade experts like Julian Hinz from the Kiel Institute for the World Economy favor such an approach.
"Dropping tariffs bilaterally between the US and the EU most definitely would be the best outcome. Having cheaper trade between those two economies would benefit both of them, whereas the flip side, if we have tariffs, 20% on each side, that increases costs for both sides. Import tariffs are an import tax that can be lowered very quickly, very easily."
On the day he announced the new measures, US President Donald Trump suggested he could be open to "zero tariffs."
"To all of the foreign presidents, prime ministers, Kings, Queens, ambassadors, and everyone else who will soon be calling to ask for exemptions from these tariffs, I say terminate your own tariffs, drop your barriers."
Conventional wisdom says there are no winners in a trade war.
Europe is keenly aware that businesses and consumers on both sides of the Atlantic stand to lose if Brussels retaliates in a way that raises the risk of a trade war of tit-for-tat tariffs.
Calls for zero tariffs — a free trade zone between the EU and the US — are growing louder from business, but it will have to be the will of the politicians before it can become a reality.