미국-멕시코 국경장벽

A boy looks at the border wall, topped with razor wire and bathed in floodlights from the U.S. side, as he walks on the beach Monday, Jan. 7, 2019, in Tijuana, Mexico. With no breakthrough in sight, President Donald Trump will argue his case to the nation Tuesday night that a "crisis" at the U.S.-Mexico border requires the long and invulnerable wall he's demanding before ending the partial government shutdown. (AP Photo/Gregory Bull)