BRUSSELS ― The French government is pushing for the European Union to issue joint debt to pay for increased military spending and is pitching the radical idea to its European counterparts, according to a confidential letter seen by POLITICO.

In the diplomatic note, likely to spark fierce opposition in some capitals ― especially Berlin ― France says the EU must "make up for decades of underinvestment in its defense and its defense industry.”

The letter, dated March 14, has been sent to several foreign ministries. Paris wants more countries to get on board before it sends an official version to the EU's top diplomat, Josep Borrell. The letter could change before then.

The war in Ukraine and increased tensions in other global hotspots coupled with the prospect of Donald Trump's return to the White House has sharpened the focus on defense issues in Europe, which has lagged behind the U.S. in military spending.

In the letter, France lists the ways in which the EU needs to step up funding, including through the issuing of joint debt ― an echo of the controversial tool it used to finance its post-Covid recovery programs and which several of the bloc's leading figures said would be a one-off.

France also puts forward the use of profits generated by frozen Russian assets, enabling the European Investment Bank to lend for defense projects and "the mobilization of private savings via further development of the EU capital markets union.”

EU leaders are on Thursday set to discuss speeding up and intensifying military assistance to Ukraine. | Axel Heimken/AFP via Getty Images

“There are several avenues worth exploring, individually or combined to each other,” the letter says. “War is back on our continent."

France, with other countries such as Estonia, which has a land border with Russia, has been pushing for defense bonds to boost the industry — an idea opposed by Germany, the Netherlands and Nordic countries. Berlin and the Hague have long been wary of the economic implications of the EU issuing joint debt.

“We acted with solidarity and put in place unprecedented instruments” in response to the pandemic, which plunged the EU into the deepest recession since the Second World War, the letter says. “In the face of Russia's aggression, we are also making history."

Leaders will discuss defense spending at Thursday's summit

EU leaders are on Thursday set to discuss speeding up and intensifying military assistance to Ukraine, whose war with Russia has entered its third year. Kyiv is running low on ammunition and has had to retreat from some points on the Russian front.

The latest draft of a statement that leaders will issue at the end of their summit in Brussels this week also hints at issuing EU debt.

“The European Council invites the Council and the Commission to explore all options for mobilizing funding and report back by June,” the draft conclusions, also seen by POLITICO, say.

Jacopo Barigazzi contributed reporting from Brussels.