Pollsters have observed a consistent enthusiasm gap between supporters of President Trump and former Vice President Joe Biden. Any factor that dampens Democratic turnout could contribute to a second come-from-behind victory for the GOP.             Adding to liberal voters’ ambivalence over Biden is a rarely-discussed aspect of Trump’s presidency. Trump’s skepticism of foreign military entanglements places him to the left of mainstream Democrats like Biden. His foreign policy aligns more closely to those of the progressives who are licking their wounds from the primary defeat of Bernie Sanders—and who are considering whether or not to vote at all.             In 2016 Trump upended traditional right-wing politics by campaigning against the Iraq War—during the Republican primaries, where candidates usually compete to look tough. This year the surprise dove can take credit for extricating the U.S. from its longest war, the 18-year-old meatgrinder of Afghanistan. Not only was Trump the first post-9/11 president to hold direct talks with the Taliban, he concluded…