In 2017, Ziemer joined President Donald Trump‘s National Security Council as Senior Director for Global Health Security and Biothreats.[8] His responsibilities in the role included preparedness against infectious diseases, including leading the response in case of a pandemic and strategies for defense against biological weapons.[9] On May 8, 2018, he unexpectedly left the post and his position was abolished by the newly appointed National Security Advisor John Bolton, in what Bolton described as part of a plan to streamline the National Security Council and merge duplicate offices.[10][11][12][13]
