Nuclear weapons

This Friday, June 26, 2020, photo combo from the European Commission's Sentinel-2 satellite shows the site of an explosion, before, left, and after, right, that rattled Iran’s capital. Analysts say the blast came from an area in Tehran’s eastern mountains that hides a underground tunnel system and missile production sites. The explosion appears to have charred hundreds of meters of scrubland. (European Commission via AP)

Secretary of State Mike Pompeo arrives for a press conference at the State Department, Wednesday, June 24, 2020 in Washington. (Mandel Ngan/Pool via AP)

Marshal Billingslea, U.S. President Donald Trump's special envoy for arms control on talks with Russia's Deputy Foreign Minister Sergei Ryabkov on nuclear arms control, informs the press in Vienna, Austria, Tuesday, June 23, 2020. (AP Photo/Ronald Zak)

In this undated photo provided on Sunday, May 24, 2020, by the North Korean government, North Korean leader Kim Jong Un speaks during a meeting of the Seventh Central Military Commission of the Workers' Party of Korea in North Korea. Independent journalists were not given access to cover the event depicted in this image distributed by the North Korean government. The content of this image is as provided and cannot be independently verified. (Korean Central News Agency/Korea News Service via AP)

In this undated photo provided on Sunday, May 24, 2020, by the North Korean government, North Korean leader Kim Jong Un speaks during a meeting of the Seventh Central Military Commission of the Workers' Party of Korea in North Korea. Independent journalists were not given access to cover the event depicted in this image distributed by the North Korean government. The content of this image is as provided and cannot be independently verified. (Korean Central News Agency/Korea News Service via AP)

FILE - In this June 28, 2019, file photo President Donald Trump, right, meets with Russian President Vladimir Putin during a bilateral meeting on the sidelines of the G-20 summit in Osaka, Japan. If Trump doesn't extend the New Strategic Arms Reduction Treaty, only remaining U.S.-Russia arms control pact, or succeed in negotiating a replacement treaty, it will expire on Feb. 5, 2021. (AP Photo/Susan Walsh, File)

FILE - In this June 28, 2019, file photo, President Donald Trump and Russian President Vladimir Putin walk to participate in a group photo at the G20 summit in Osaka, Japan. The Trump administration is notifying international partners that it is pulling out of a treaty that permits 30-plus nations to conduct unarmed, observation flights over each other’s territory — overflights set up decades ago to promote trust and avert conflict. The administration says it wants out of the Open Skies Treaty because Russia is violating the pact and imagery collected during the flights can be obtained quickly at less cost from U.S. or commercial satellites. (AP Photo/Susan Walsh, File)

Russian President Vladimir Putin attends a meeting on the transport system development via video conference at the Novo-Ogaryovo residence outside Moscow, Russia, Thursday, May 7, 2020. (Alexei Nikolsky, Sputnik, Kremlin Pool Photo via AP)

In this photo released Wednesday, April 22, 2020, by Sepahnews, an Iranian rocket carrying a satellite is launched from an undisclosed site believed to be in Iran's Semnan province. Iran's Revolutionary Guard said Wednesday it put the Islamic Republic's first military satellite into orbit, dramatically unveiling what experts described as a secret space program with a surprise launch that came amid wider tensions with the United States. (Sepahnews via AP)