Just a few days after the inaugural summit between U.S. President Donald Trump and Russian President Vladimir Putin in Helsinki, Trump has already invited Putin for a follow-up summit in Washington. On July 20, Russian officials confirmed that Moscow is considering the meeting. Trump said the first summit was "only the beginning" of longer negotiations on numerous contentious issues between the two countries, including arms control, Syria and Ukraine. And the Russian president already appears to be using the conflict in Ukraine to rev up the talks....