National Security

The TikTok app logo is pictured in Tokyo, Sept. 28, 2020. University of Wisconsin System officials said Tuesday, Jan. 24, 2023, that they will restrict the use of TikTok on system devices. Kiichiro Sato/AP hide caption

British Army Challenger 2 tanks are seen at a training ground in Poland on Sept. 21, 2022. This week, Ukrainian soldiers have arrived in the United Kingdom for training on the Challenger 2. Artur Widak/NurPhoto via Getty Images hide caption

U.S. Attorney General Merrick Garland speaks during a news conference with Deputy Attorney General Lisa Monaco (left), and FBI Director Christopher Wray at the Department of Justice in Washington on Thursday. Ting Shen/Bloomberg via Getty Images hide caption

A new report from the U.S. Secret Service analyzes 173 mass attacks that took place in the country from 2016-2020. It comes just days after two shootings in California – in Monterey Park and Half Moon Bay – killed 18 people. Shown here is a mourner at a candlelight vigil for victims of the mass shooting at a dance studio in Monterey Park, Calif. Qian Weizhong/VCG via Getty Images hide caption

U.S. Abrams tanks participate in a live fire demonstration during training exercises in Poland in September 2022. President Biden announced Wednesday that the U.S. will be sending 31 Abrams tanks to Ukraine. Germany also said it will be sending tanks. Omar Marques/Getty Images hide caption

German Chancellor Olaf Scholz stands next to a Leopard 2 main battle tank of the German armed forces while visiting an army training center in Ostenholz, Germany, on Oct. 17, 2022. David Hecker/Getty Images hide caption

A man plays violin on the sidelines of a religious service held by local residents in front of an apartment building in the Ukrainian city of Dnipro on Sunday. The building was destroyed by a Russian missile strike on Jan. 14. Anatolii Stepanov/AFP via Getty Images hide caption

Rioters try to open a door of the U.S. Capitol on Jan. 6, 2021. Three active-duty Marines have been charged in the attack. Jose Luis Magana/AP hide caption

A German Leopard 2 battle tank pictured during a NATO training exercise in Lithuania last October. Sean Gallup/Getty Images hide caption

U.S. Defense Secretary Lloyd Austin (left) and the chairman of the Joint Chiefs of Staff, Gen. Mark Milley, discuss details of a huge U.S. and NATO arms package for Ukraine at the U.S. air base in Ramstein, Germany, on Friday. ANDRE PAIN/AFP via Getty Images hide caption

Two Leopard 2 A6 heavy battle tanks and a Puma infantry fighting vehicle of the Bundeswehr's 9th Panzer Training Brigade participate in a demonstration of capabilities during a visit by then-Defense Minister Christine Lambrecht to the Bundeswehr Army training grounds in February 2022 in Munster, Germany. Sean Gallup/Getty Images hide caption