Even as they insist they are not dancing to Donald Trump's tune on NATO, European leaders are singing from a song sheet designed to appeal to the former U.S. president and his Republican supporters.

Trump sparked fierce criticism from Western officials for suggesting he would not protect countries that failed to meet the transatlantic military alliance's defense spending targets, and would even encourage Russia to attack them.

At the weekend, the comments by the front-runner for the Republican presidential nomination hung over the Munich Security Conference, a big annual gathering of politicians, soldiers and diplomats that is often a barometer of U.S.-European relations.