The North Atlantic Treaty Organization (NATO) is comprised of 29 individual countries. The organization was founded in 1949 to primarily halt the expansion of Communism. In 2014, the member nations agreed to spend at least 2% of their Gross Domestic Product (GDP) on defense expenditures. Unfortunately, many of the nations are not yet spending the amount that they pledged they would.
Although many analysts believe the arbitrary 2% guideline is not important, it does illustrate the importance some countries place on security versus others. The United States, Greece, Estonia, Poland and the UK are the top five contributors while Canada, Luxembourg, Belgium, Slovenia and Spain contribute the least.