More Republicans are speaking out against President Donald Trump’s decision to let Vladimir Putin’s Russia temporarily export diesel fuel on the global market, expanding the bipartisan blowback over the deal. Six GOP senators joined six of their Democratic colleagues in a letter Tuesday urging Trump to cancel the arrangement allowing Russia to supply 4.8 million metric tons, or nearly 36 million barrels, of diesel through mid-April. “This deal is a gift to our adversary and a betrayal of our Allies; it should be rescinded,” the lawmakers wrote. Republican Sens. Thom Tillis of North Carolina, Susan Collins of Maine, Oklahoma’s Alan...