France and Poland’s reconciliation is a sign of Europe’s alarm over US disengagement

Treaty of Nancy will be signed on Europe Day , in the town hall on the 18th-century Place Stanislas .

It will cement a reconciliation between two countries that have been estranged within the EU for decades .

Poland has long relied exclusively on the US and Nato for its security and has resisted any EU role in defence.

France will never share control of its 290 nuclear warheads, most of which are based on submarines.

But Paris keeps dropping hints that it is open to extending its umbrella to European allies.

To do so, it would need more costly warheads and launchers than it owns now.

That might require European co-financing or some trade-off to help France raise defence spending.