The US has threatened to pull troops out of Germany as differences between the two countries on policy on the Middle East and Nato spending become more stark.
The US ambassador to Berlin’s strong words on Friday appeared to be a response to Germany not meeting the 2 per cent Nato target and more recently the European country refusing to take part in a US-led naval mission in the Arabian Gulf in response to the growing Iranian threat.
"It is really insulting to expect that the US taxpayer pays for more than 50,000 Americans in Germany, but the Germans use their trade surplus for domestic purposes," US Ambassador to Germany Richard Grenell told local media on Friday.
Last week, German Foreign Minister Heiko Maas said Berlin wouldn’t participate in the mission, considering “the US strategy of maximum pressure on Iran to be wrong".
But Germany is the European country where the US military has the most presence. Some 35,000 soldiers are stationed there along with 17,000 American civilians who work in the military. As well as this, 12,000 German civilians work in jobs connected to the US military.
Tensions between Germany and the US have been rising over Nato spending for some time now, but disagreements how to counter the threat of Tehran brought defence back into the spotlight.
Germany intends to contribute 1.36 per cent of its GDP to defence spending this year. It plans to increase it to 1.5 per cent in 2024, but this is still way off the Nato target of 2 per cent target for each member of the alliance by 2025.
The US is one of three Nato members that exceeds the threshold, spending 3.6 per cent of its GDP on defence.
On Thursday, Georgette Mosbacher, the US ambassador to Warsaw, highlighted in a tweet that Poland meets its 2 per cent Nato spending commitment, while Germany does not.
She said that because of this, “we would welcome American troops in Germany to come to Poland.”
Mr Grenell said he agreed with Ms Mosbacher’s comments.
Although Poland has a higher GDP percentage allocated to defence spending, Germany’s total GDP – being the largest economy in Europe - is nearly seven times more than Poland’s.
But US President Donald Trump has been a long-time critic of Berlin’s Nato defence spending, saying that the country relies on Washington’s support to protect it from Moscow.
Like Ms Mosbacher, the American leader also entertained the idea of moving some of Germany’s US troops to Poland. Mr Trump brought it up in talks country’s president Andrezej Duda in Washington in June.
Mr Trump will meet German Chancellor Angela Merkel at the G7 summit in the French town of Berritz at the end of the month. He will also be visiting Denmark and Poland from August 31 to September 3.