Trump heads to Brussels for NATO summit amid tension with allies
U.S. allies are bracing for President Trump at this week's NATO summit in Brussels. The president slammed the decades-old military alliance, saying the U.S. spends more on it than any other country and that it's unfair to taxpayers. Gabe Lipton, a CBSN contributor and Signal newsletter writer for GZERO Media, explains NATO's relevance in 2018.