North Partnership Council which helps partners to become

North Atlantic Treaty Organization or in other words NATO is a union of nations from Europe and North America, it gives a unique link between these two continents, enabling them to consult and coordinate in the field of guard and security, and lead multinational emergency administration operations together. The intergovernmental association provides a forum where individuals can consult together on any issues they raised and take choices on political and military issues influencing their security. NATO’s primary purpose was to defend member nations against troops in pro-communist countries and to defend the freedom and security of every one of its members by political and military means. NATO is commited on the principle of collective security, in Article 5 of the Washington Treaty, an assault against one or a few individuals is considered as an assault against all. Collective security are the main focus of the Alliance and creates a spirit of solidarity and attachment among its members. 

NATO currently has 29 individuals so far which is: Albania, Belgium, Bulgaria, Canada, Croatia, Czech Republic, Denmark, Estonia, France, Germany, Greece, Hungary, Iceland, Italy, Latvia, Lithuania, Luxembourg, Montenegro (2017), Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Turkey, United Kingdom and the United States. NATO also partook in three alliances which are the Euro-Atlantic Partnership Council which helps partners to become NATO members. The Mediterranean Dialog seeks to stabilize the Middle East. The Istanbul Cooperation Initiative works for peace all throughout the larger Middle East region. 

After World War II in 1945, western Europe was financially depleted and militarily weak(the western Allies had quickly and rapidly reduced their armies toward the end of the war), and the newly powerful communist parties had emerged in France and Italy. By contrast, the Soviet Union had emerged out of the war with its armies dominating all the states of central and eastern Europe, and by 1948 the communists had consolidated their control of the governments of those nations and suppressed all noncommunist political activity to what become known as the Iron Curtain, a term popularized by Winston Churchill. Further, wartime cooperation between the western Allies and the Soviets had totally separated. Each side was sorting out that German would be divided, a democratic one in the west and a communist one in the east. In 1948 the United States launched the Marshall Plan, which infused enormous amount of economic aid to the nations of western and southern Europe on the condition that they collaborate with each other and take part in joint intending to hasten their mutual recovery. With respect to military recovery, under the Brussels Treaty of 1948, the United Kingdom, France, and the Low Countries—Belgium, the Netherlands, and Luxembourg—concluded a collective-defense agreement called the Western European Union. It was soon concluded that a more formidable alliance would be required to give a satisfactory military counterweight to the Soviets. At this point Britain, Canada, and the United States had already engaged in secret exploratory talks on security arrangement of action that would serve as an alternative to the United Nations (UN), which was becoming paralyzed by the rapid rising of the Cold War. On February 1948, the three governments started talks on a multilateral collective defense scheme that would enhance Western security and promote democratic values. These discussion were then joined by France, the Low Countries, and Norway and in April 1949 which at that point brought in the North Atlantic Treaty. 

NATO is a crisis management organisation that has the capacity to undertake a wide range of military operations and missions. After the Cold War, NATO directed a few other military operations: 

Operation Anchor Guard (10 August 1990 – 9 March 1991) – NATO Airborne Early Warning air ship conveyed to Konya, Turkey, to monitor the crisis and provide coverage of southeastern Turkey if there should be an occurrence of an Iraqi attack  during the amid of a Gulf Crisis/War. 
Operation Allied Goodwill I and II (4-9 February and 27 February – 24 March 1992)  – NATO helped a worldwide alleviation exertion by flying groups of compassionate help specialists and therapeutic consultants to Russia and other Commonwealth of Independent States countries utilizing AWACS  mentor load flying machine. 

Currently, NATO is operating in Afghanistan, Kosovo and the Mediterranean.

NATO are currently leading Resolute Support, a non-combat mission which gives training, guidance and assistance to Afghan security forces and institution. Resolute Support was launched on 1 January 2015. Key functions may include: supporting planning, programming and budgeting; assuring transparency, accountability and oversight; supporting the adherence to the principles of rule of law and good administration; supporting the establishment and sustainment of processes such as force generation, recruiting, training, managing and development of personnel.
NATO immediately began to take measures to grow the options available to counter the danger of international terrorism in the Meditteranean Sea with Sea Guardian. It is helping to maintain a secure and safe maritime environment while supporting the Alliance’s three core tasks: collective defence, crisis management and cooperative security.

Even with all these successes, NATO has always struggled with the uneven distribution of the alliance’s defense spending. Since Europe has been fairly peaceful in late decades, and because European NATO states are under the American defense umbrella, they haven’t expected to commit all of their resources to their own security. Futhermore, the new members don’t have military strength or economic power, some NATO members are concerned about old rivalries than really addressing the needs of one united defensive force.

All in all, NATO has been highly successful for many nation members (particularly European) who aren’t as military centric as the United States, because they enjoy an umbrella of protection that their Western superpower co-member provides. I’d also say that it benefits the United States in a different way, by allowing the U.S. to project a global presence close to the borders of non members (particularly Russia).