Defender-Europe 21

Defender-Europe 21 was a large-scale, United States Army-led, multinational joint exercise designed to build readiness and interoperability between the United States, NATO and partner militaries.{{cite web |last1=Jensen |first1=Juli-anne |title=V Corps arrives in Europe for Defender-Europe 21 |url=https://www.army.mil/article/246673/v_corps_arrives_in_europe_for_defender_europe_21 |website=www.army.mil |access-date=March 24, 2022 |language=en |date=May 20, 2021}} Taking place between mid-March and June, it was one of the largest United States Army, NATO-led military exercises in Europe in decades. More than 28,000 personnel from 26 nations conducted nearly simultaneous operations across more than 30 training areas in a dozen countries.{{cite news |last=South |first=Todd |title=Massive, Army-led NATO exercise Defender Europe kicks off |url=https://www.armytimes.com/news/your-army/2021/03/15/massive-army-led-nato-exercise-defender-europe-kicks-off/ |work=Army Times |date=15 March 2021}}{{cite news |title=NATO, US to stage large-scale military exercises around Serbia until summer |url=https://www.euractiv.com/section/politics/short_news/nato-us-to-stage-large-scale-military-exercises-around-serbia-until-summer/ |work=Euractiv |date=22 March 2021}}

It included a greater number of NATO and partner nations conducting activities over a wider area than what was planned for in 2020. Defender-Europe 21 also included significant involvement of the United States Air Force and United States Navy. The exercise utilized key ground and maritime routes bridging Europe, Asia and Africa. It incorporated new or high-end capabilities including air and missile assets, as well as assets from the United States Army Security Force Assistance Brigades and the recently reactivated V Corps.{{cite web |title=Press Release - Defender-Europe 21 activities begin this month, include two dozen nations |url=https://www.europeafrica.army.mil/ArticleViewPressRelease/Article/2537359/press-release-defender-europe-21-activities-begin-this-month-include-two-dozen/ |website=U.S. Army Europe and Africa |access-date=March 24, 2022 |date=March 15, 2021}} {{PD-notice}}

Gen. Christopher G. Cavoli, commanding general of the United States Army Europe and Africa, said that "While we are closely monitoring the COVID situation, we've proven we have the capability to train safely despite the pandemic." Russian Defense Minister Sergey Shoigu said that Russia has deployed troops to its western borders for "combat training exercises" in response to NATO "military activities that threaten Russia."{{cite news |title=Germany Says Russia Seeking To 'Provoke' With Troop Buildup At Ukraine's Border |url=https://www.rferl.org/a/russia-ukraine-military-germany-nato/31203229.html |work=Radio Free Europe/Radio Liberty |date=14 April 2021}}