Zach Johnson , who won the 2007 Masters , said he did not want to take the risk following North Korea 's recent threats against its neighbor and its move to test missiles and restart its nuclear program . Dustin Johnson and Zach Johnson withdrew from golf tournament in South Korea . American players worried about recent tensions on the Korean peninsula . Tournament sponsor insists that the event can safely go ahead this week . Women 's tournament is co - sanctioned by European and Asian tours .
Dustin Johnson and Zach Johnson withdrew from golf tournament in South Korea . American players worried about recent tensions on the Korean peninsula . Tournament sponsor insists that the event can safely go ahead this week . Women 's tournament is co - sanctioned by European and Asian tours .