Trump splits with GOP lawmakers on national security, raising alarm

National security-minded Republican lawmakers are alarmed by what they see as a growing split between themselves and former President Trump on key issues, including the war in Ukraine, preserving the NATO alliance and protecting Taiwan from Chinese aggression.

Trump’s actions over the past three weeks have stirred confusion and concern among Republican senators who voted earlier this year to approve tens of billions of dollars to contain Russia’s invasion of Ukraine and to deter China from attacking Taiwan, an important U.S. ally and trading partner.

Defense-minded GOP senators viewed Trump’s...