America has been forced to turn to France to plug a critical gap in US navy capabilities in the Gulf because the Royal Navy has no active aircraft carriers to send, the Times reported on Monday.

When the American aircraft carrier Theodore Roosevelt finishes her present deployment with the US Fifth Fleet in the autumn, the Pentagon will rely on the flagship of the French navy — the Charles de Gaulle — to fill the resulting shortfall in carrier capacity in the region.

The decision underlines American frustration at what is seen in Washington as Britain’s retreat on the world stage. US diplomats have taken to referring to “Great shrinking Britain” as they lament defense cuts and a reluctance by David Cameron to take a lead in global affairs.

That the Pentagon will turn to Paris for an aircraft carrier, while the US flies sorties against Daesh in Iraq and Syria, will cement perceptions that France has displaced Britain to become Washington’s most trusted military ally.