Ahead of President Trump's summit with North Korean leader Kim Jong un in Vietnam this week, there are growing concerns about the strength of Washington's alliance with Seoul. This is due to Trump's repeated statements that the American military presence in South Korea
and Japan is too expensive and that both countries need to pay more.
Observers do not expect the U.S.-South Korean alliance to come under direct threat during the Hanoi summit but it's possible that Trump could withdraw some of the troops deployed on the peninsula
. The following infographic provides an overview of U.S. troop levels in South Korea over the past decade and as of September 2018, 29,383 active duty and reserve personnel were based there, according to DMDC data