The Democrats are about to remind us that while Donald Trump has great freedom in foreign policy, it’s Congress which holds the purse strings

One of the main prerogatives of the presidency compared to Congress is its freedom in foreign policy: to make treaties, negotiate agreements and to deploy troops. But while Congress cannot set foreign policy, writes Jeremi Suri, it can influence it through the power of its purse. He argues that from now until at least 2020, we should expect push back from Congressional Democrats on President Trump’s nationalistic rhetoric as well as on his trade and military agendas.