Little Marco, now Secretary of State Marco Rubio, got his first marching orders from Donald Trump: Go to Panama and talk the Panamanians into giving up the Panama Canal. Panama is very unlikely to do that, since canal tolls are an important source of revenue for the government. Also, Panama is a well-run, moderate-income, pro-U.S. country in a region where not many countries fit that model. Panamanians are proud of that and don't like being bossed around.
But if Rubio comes home empty-handed on his first mission, Trump will be furious and might send the Marines in. Panama's president, José Raúl Mulino, understands that, so he has to give Rubio something to show for his efforts. It might be something as small as allowing U.S. warships through for free or rolling back China's presence at the ports on both ends of the canal.
Mulino can also threaten, if pushed too hard. Right now, Panama tries to block would-be immigrants to the U.S. from Colombia and farther south at the border. He could decide to let them in and have them safely escorted to Costa Rica. That would cause Trump headaches. Of course, that is a last resort. Mulino hopes to buy Rubio off with smaller concessions that Trump can brag about as a "win." (V)