Treading carefully and with a soft touch, NATO (whose future has been questioned by the president of the United States, Donald Trump) will celebrate its 70th birthday this week in Washington. The anniversary offers the military alliance the opportunity to launch a charm offensive to try and demonstrate to the president that NATO not only benefits the security of Europe but also that of the United States. The secretary general of the organization, the Norwegian Jens Stoltenberg, will lead the campaign.

Stoltenberg will meet Trump at the White House on Tuesday where they are planning a joint press conference.* On Wednesday, the NATO secretary general will address a joint session of the two chambers of the U.S. Congress; deference towards a foreign leader previously demonstrated only once since 2017, with French President Emmanuel Macron.

The visit will end on Thursday with a summit at the ministerial level to commemorate the signing of the Treaty of Washington which took place on April 4, 1949. This was the founding act of NATO, one of the supranational institutions that has shaped the Western political order since World War II. The meeting will be attended by foreign ministers — a rank which lowers the bar for acts of commemoration — at a time when the relationship between European allies and the U.S. is in a fragile state.

But Stoltenberg arrives in Washington backed by figures that show an increase in defense spending by European allies, a long-standing U.S. demand which Trump has turned into a mantra. The provisional data for 2018 shows, that for the fourth consecutive year, there has been an increase in expenditure, to $281 billion (some 250 billion euros). In terms of percentage of GDP, it grew from 1.42% in 2014 to 1.51% in the previous year, with an accumulated increase over a four-year period of more than 13%.

Support for how this has been managed was demonstrated last week when the Alliance extended Stoltenberg’s mandate for another two years until Sept. 30, 2022.

"In 2014, only three allies spent 2% of GDP on defense. In 2018, seven allies have met that goal of 2%, and Romania is very close," said Stoltenberg on March 18, at a conference in Brussels. NATO estimates that the additional contribution to the defense budgets of the European allies and Canada will reach 100 billion euros from 2016 to the end of 2020.

NATO's European partners also want to convince the U.S. that the defense of the trans-Atlantic link continues to make geostrategic sense on both sides of the ocean. Diplomatic sources emphasize that the stability of the “Old Continent” guarantees to the U.S. the security on one of its main flanks, which allows the superpower to turn its attention to other areas of the planet. The argument has many followers in the U.S. Congress, both in the Republican and the Democratic caucuses. But it does not seem to fully convince the White House, where the periodic leaks that question the strength of the historic trans-Atlantic alliance emerge from. The plans supposedly on the table have ranged from the U.S. leaving NATO, to charging for the bases its armed forces have in several European countries, including Spain.

But the main obstacle to Stoltenberg's campaign of seduction goes by the name of Germany; a country that despite its healthy accounts continues to delay the goal of 2% defense spending. German figures for 2018 stand at 1.23%, far from the 1.82% of France or the 3.39% of the U.S.

"Germany has after years of cutting defense spending started to increase; and actually added a significant amount of money to the defense budgets," stressed Stoltenberg during the presentation of the 2018 annual report in Brussels in March. Berlin has assured the alliance that in order to reach the 2% expenditure target during the fixed term (between 2014 and 2024), the German defense budget will increase by 80%. A considerable figure, but one which still might not be enough for Trump, who continually asks the question of what the Europeans do for NATO.

*Editor’s note: President Trump and Secretary General Stoltenberg met on April 2, 2019. They discussed the fight against terrorism and efforts to ensure that expenditures are fairly divided within the Alliance.