Here are the 30 NATO countries, sorted by their military workforce (with how much they spend on defense as a percentage of their GDP in parentheses):

United States (Member since 1949): 1,351,500 (3.57)

Turkey (1952): 439,100 (1.6)

France (1949): 207,500 (1,93)

Germany (1955, all of Germany from 1990): 184,800 (1,49)

Italy (1949): 175 300 (1.54)

United Kingdom (1949): 156,200 (2.25)

Poland (1999): 121,000 (2.34)

Spain (1982): 119,000 (1.03)

Greece (1952): 109,700 (3,59)

Canada (1949): 71,100 (1.36)

Romania (2004): 68 600 (1.88)

Netherlands (1949): 40,800 (1,45)

Czech Republic (1999): 26,400 (1,4)

Bulgaria (2004): 26,000 (1.62)

Portugal (1949): 24,100 (1.55)

Belgium (1949): 22 700 (1.07)

Norway (1949): 22 200 (1.74)

Hungary (1999): 19,800 (1,69)

Denmark (1949): 17,000 (1.4)

Lithuania (2004): 16,700 (2.03)

Croatia (2009): 14,400 (2,16)

Slovakia (2004): 13,100 (1.73)

Estonia (2004): 6,800 (2,16)

Albania (2009): 6,600 (1,41)

Latvia (2004): 6,600 (2,16)

Northern Macedonia (2020): 6,100 (1.54)

Slovenia (2004): 6,000 (1.22)

Montenegro (2017): 1,700 (1.63)

Luxembourg (1949): 800 (0.54)

Footnote: Iceland has also been a member since 1949 but has no defense of its own.

Source: NATO Annual Report

NATO’s first military commander (called Saceur – Supreme Allied Commander Europe) was Dwight Eisenhower from the United States, with British Bernard Montgomerie as deputy chief.

The Saceur post has since always been held by Americans – right now by former fighter pilot and Air Force General Tod Wolters, who this summer will be replaced by Army General Chris Cavoli.

Civilian, NATO Secretary General is the supreme commander. Here are the leaders of recent years:

Since 2014: Jens Stoltenberg, Norway

2009-14: Anders Fogh Rasmussen, Denmark

2004-09: Jaap de Hoop Scheffer, The Netherlands

1999-2004: George Robertson, UK

1995-99: Javier Solana, Spain

1994-95: Willy Claes, Belgium

1988-94: Manfred Wörner, Germany.

Source: NATO