In March 2019, when the Green New Deal came up for a vote in the Senate, Warren and 41 other Senate Democrats voted "present", which was anticipated as ahead of the vote as a means of most Democrats not having to take a formal position on the legislation. In April 2019, Warren sent a letter to Chairman of the Joint Chiefs of Staff Gen. Joseph Dunford asserting that the Defense Department "must do more than simply acknowledge or take piecemeal actions to address climate change while it increasingly threatens and harms our military's infrastructure and operations" and that the US adapting to climate change was "a necessary component of maintaining readiness." She recounted the testimonies of high ranking military officials to the Senate Armed Services Committee, noting that they all "acknowledged the threat of climate change to our military’s infrastructure and operations, and that adapting to climate change is a factor in military readiness", citing this "uniformity of opinion among military leaders" as underscoring her position on "the need to act vigorously and expeditiously to mitigate this threat." Warren requested that Dunford submit summaries of the Pentagon's approach to building resistance to climate change risks and curbing it as well as an update on implementation of the GAO recommendations. In March 2018, during a three-day visit to Beijing, Warren claimed that US policy encouraging the opening of markets in China through free trade has not been successful. She advocated against the United States having a more integrated economic system with China if the latter country continued failing "to respect basic human rights". In November 2018, Warren joined Senators Chris Coons, Marco Rubio and a bipartisan group of lawmakers in sending a letter to the Trump administration raising concerns about China’s undue influence over media outlets and academic institutions in the United States. They wrote: "In American news outlets, Beijing has used financial ties to suppress negative information about the CCP. In the past four years, multiple media outlets with direct or indirect financial ties to China allegedly decided not to publish stories on wealth and corruption in the CCP...Beijing has also sought to use relationships with American academic institutions and student groups to shape public discourse." Warren and some other members of Congress introduced legislation seeking to punish China over its human rights abuses against the Uyghurs and other predominantly Muslim ethnic minorities in China's north-western province of Xinjiang. China may have imprisoned as many as 1 million Muslims in re-education camps, according to a UN estimate. In February 2019, amid a report by the Commerce Department that ZTE had been caught illegally shipping goods of American origin to Iran and North Korea, Warren was one of seven senators to sponsor a bipartisan bill reimposing sanctions on ZTE in the event that ZTE did not honor both American laws and its agreement with the Trump administration.