WASHINGTON — President Trump’s White House counterterrorism director Sebastian Gorka told The Post that he believes China intentionally flooded the United States with fentanyl in a present-day “Opium War” designed to weaken America through the “targeted killing” of its citizens. Gorka unloaded the blistering assessment Monday in a “Pod Force One” interview with The Post’s Miranda Devine — before Trump departed Tuesday afternoon for a state visit to Beijing that is expected to focus on trade relations . “They see our city on a hill as the newest version of the British Empire, and it is now payback time for the Opium Wars. Many have said that, and I think there is something to that,” Gorka said. White House official Sebastian Gorka said in an interview on “Pod Force One” that China intentionally flooded the United States with fentanyl in a present-day “Opium War.” New York Post “This is about how do you take down a Goliath? What is the slingshot?…