close Video Defense Secretary Mark Esper on challenges to US national security ‘Fox News Sunday’ exclusive: Defense Secretary Mark Esper joins Chris Wallace for a wide-ranging interview at the Reagan National Defense Forum. This is a rush transcript from “Fox News Sunday,” December 8, 2019. This copy may not be in its final form and may be updated. Chris Wallace, anchor: I’m Chris Wallace. A Saudi air force officer targets Americans at a military base killing three members of the U.S. Navy. We’ll discuss that and the challenges to U.S. national security in an exclusive interview with the secretary of defense. [BEGIN VIDEOTAPE] In this hour, we’ll drill down on the threat from Tehran. The Iranians continue to ship missiles around the area to Iraq, to Yemen. What would more troops do? And President Trump’s promise to pull U.S. troops out of endless wars. We seem to be pulling back from fighting terrorism where Ronald Reagan was leaning forward. We’re joined by Defense Secretary Mark Esper here at the Reagan National Defense Forum only on “Fox News Sunday.” Then – House Speaker Nancy Pelosi: Today, I am asking our chairman to proceed with articles of impeachment. Chris Wallace: House Speaker…