The US president and the German chancellor have locked horns . Spain has shunned Washington. The Nato alliance is more fragile than it has ever been. Western powers are determined to see off Russian military “hard” power; they are familiar with “soft power” operations to undermine democracies. But how to deal with the Kremlin’s relationship with Donald Trump is now an emergency. Working out a response to internal frictions within Nato has become a conundrum, not only for leaders in the alliance but for the military officials who have to figure out how to keep the military machine operational. A weakened Nato serves only the interests of the enemies and rivals of the West. Top of the list of beneficiaries is Vladimir Putin , but China will enjoy the latest spats between Trump and Germany’s Friedrich Merz almost as much.…