NATO Secretary-General Mark Rutte walks into the White House, as seen through a fence, in Washington on April 8. | REUTERS BRUSSELS – European officials have been working on ways to convince U.S. President Donald Trump to keep the United States in NATO despite severe tensions over the Iran war. But his abrupt move to cut U.S. forces in Germany is the latest sign that such efforts have their limits and are far from certain to succeed. The substance of the decision announced on Friday to remove 5,000 troops from Germany did not come as a surprise to NATO officials. European leaders have agreed with the U.S. president that Europeans will take over more responsibility for their own security from U.S. forces. Dropping a plan to deploy long-range U.S. Tomahawk missiles to Germany was more concerning for Berlin. But even that was not a huge shock, as that deal was made by Trump’s predecessor, Joe Biden, and U.S. Tomahawk stocks have been depleted by the U.S.-Israeli war against Iran.…