In War on Peace: The End of Diplomacy and the Decline of American Influence, Ronan Farrow writes about his time at the State Department and describes what he sees as a dangerous whittling away of the agency's influence. Alex Wong/Getty Images hide caption
CIA Director Mike Pompeo (right) is President Trump's choice to replace Rex Tillerson, who has been fired as secretary of state. Chris Kleponis/Pool/Getty Images; Joe Raedle/Getty Images hide caption
A man at the Seoul, South Korea, train station last August watches a news program featuring President Trump and North Korean leader Kim Jong Un. Ahn Young-joon/AP hide caption
President Trump and North Korean leader Kim Jong Un are expected to continue to square off in 2018. Evan Vucci, Wong Maye-E/AP hide caption
Secretary of State Rex Tillerson makes his way to his seat before the Strategic Dialogue on Disrupting Transnational Criminal Organizations at the State Department on Dec. 14. Nicholas Kamm/AFP/Getty Images hide caption
Secretary of State Rex Tillerson could be replaced by CIA Director Mike Pompeo in as soon as a few weeks, according to multiple media reports. Mandel Ngan/AFP/Getty Images hide caption
Secretary of State Rex Tillerson, with Secretary of Defense Jim Mattis, testifies during a Senate Foreign Relations Committee hearing on Congress's power to authorize the use of military force. Manuel Balce Ceneta/AP hide caption
Secretary of State Rex Tillerson met with Indian Prime Minister Narendra Modi in New Delhi on Oct. 25. Alex Brandon/AFP/Getty Images hide caption
U.S. Secretary of State Rex Tillerson steps off the plane as he arrives in Qatar after returning from Bagram Air Base in Afghanistan on Monday. Tillerson paid a surprise visit to Afghanistan to meet with President Ashraf Ghani and other officials. Alex Brandon/AFP/Getty Images hide caption
Mission San Jose, one of five missions in San Antonio designated by UNESCO as a World Heritage Site. The cultural aid agency has designated more than 1,000 such sites around the world — including more than 20 in the U.S. — to celebrate their "outstanding universal value." Eric Gay/AP hide caption
Secretary of State Rex Tillerson said at a briefing Wednesday that a news report that he intended to resign was "intended to divide" and that he was "not going to deal with petty nonsense." Jim Watson/AFP/Getty Images hide caption
President Trump in Morristown, N.J., in September and Kim Jong Un following a military parade in Pyongyang earlier this year. Mandel Ngan/AFP/Getty Images hide caption
The State Department is suspending visa services at the U.S. Embassy in Havana indefinitely. Desmond Boylan/AP hide caption
Secretary of State Rex Tillerson says North Korea's Kim Jong Un "doesn't seem to understand diplomatic language." Vincent Thian/AP hide caption