London and Berlin on Wednesday hailed a “milestone” in military cooperation, as they signed a new defence pact that would see German submarine-hunting planes operate from British bases and counter threats from Russia after its full-scale invasion of Ukraine. Europe’s two biggest defence spenders said the Trinity House Agreement, signed by defence ministers John Healey and Boris Pistorius, would strengthen NATO’s “European pillar” at a time of increased threat from the east. An eye-catching part of the deal is the prospect of German Boeing P-8 aircraft patrolling the skies of the North Atlantic…