The language from European leaders was fawning and obsequious. At one point, the head of Nato, Mark Rutte, even called Donald Trump "daddy". But when the US president left the Nato summit in late June, there was a sigh of relief that he had not made any more angry criticism of the alliance.

After months of American pressure, Nato members - with the exception of Spain - agreed to increase their spending on defence to 5% of GDP by 2035. Trump called it "very big news", and even reconfirmed his commitment to Nato's article 5, which means an attack on one Nato country is an attack on them all.

How did Europe become so unable to defend itself that it was forced to resort to outright flattery of an American president?

In this episode of The Conversation Weekly podcast, we report from the recent Siena Conference on the Europe of the Future in Italy about how the EU dropped the ball on its own defence and what its options are now.

The European Commission, the executive branch of EU government, only appointed its first commissioner for defence in December 2024. There is no EU army, and no consensus as to whether democratic nations could ever allow one to be built.

But in the period after the second world war, ambitions for a united European defence policy were much grander, as Ana Juncos Garcia, professor of European politics at the University of Bristol in the UK, explains:

There was this idea to establish a European Defence Community which would pool competencies at the national level in defence to the European level, creating a supranational organisation with its own minister of defence, its own military committee.

That failed in 1954 when the French national assembly rejected ratification of the treaty and progress on a pan-European defence strategy stalled. Nato, founded in 1949, became the core military alliance organising Europe's defence, with the US as its main guarantor.

Ever since, the EU has tried to balance the need for maintaining that transatlantic relationship, and figuring out a way to organise, and procure, its own defence capabilities in a joined up way.

Listen to The Conversation Weekly podcast, which includes interviews with Francesco Grillo, academic fellow in political science at Bocconi University in Italy, and Francois Lafond, former assistant professor at Sciences Po University in Paris and former advisor to the Western Balkans on European integration.

This episode of The Conversation Weekly was written and produced by Gemma Ware with assistance from Katie Flood and Mend Mariwany. Mixing and sound design by Eloise Stevens and theme music by Neeta Sarl.

Newsclips in this episode from National Defence, NBC News, CNBCtelevision, Forbes Breaking News, CBS News and Critical Past.

Listen to The Conversation Weekly via any of the apps listed above, download it directly via our RSS feed or find out how else to listen here. A transcript of this episode is available on Apple Podcasts or Spotify.