What is it? NATO stands for the North Atlantic Treaty Organisation. It is a military alliance of 28 different countries in North America and Europe.
When was it formed? 1949.
Why? It was formed to give collective defence and security to North American and Western European states against an expanding Soviet Union and the threat of communism.
But the USSR is long gone - what does it do now? NATO has expanded in recent years. Just like the EU it has moved eastwards, encompassing nations that were formerly part of - or allied to - the USSR. It currently has an ongoing presence to promote peace and stability around the world in the likes of Kosovo, the African Union and Afghanistan.
What's Article 5? I've heard of that. Article 5 is a fundamental component of the organisation. It states that if one of the NATO countries is attacked then such an attack will be viewed as an attack on all participating countries. For example, if France was attacked then the other countries in the organisation would see the attack on France as an attack on them all. Which countries are members?
In total there are 28 members spanning two continents. North America: Canada, USA. Europe: Albania, Belgium, Bulgaria, Croatia, Czech Republic, Denmark, Estonia, France, Germany, Greece, Hungary, Iceland, Italy, Latvia, Lithuania, Luxembourg, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Turkey, United Kingdom.
The majority of the European countries in NATO also belong to the EU, however, there are notable exceptions.
What was the Warsaw Pact? The Warsaw Pact - now defunct - was a similar alliance for collective defence made up of the USSR and a number of other communist nations in Eastern Europe. How do people feel about NATO?
The organisation is popular in the UK with a recent YouGov poll suggesting that 68% of voters think that NATO still has a role in the world compared to 21% who disagree. However, according to the same poll the organisation is apparently less popular in the USA with just 46% of US voters thinking it still has a role to play in contrast to the 16% who have the opposing view.
No USSR, but NATO still has a place on the world stage! The USSR may be no longer exist and the Cold War may be officially over, but many argue that there is still a threat from Russia, making the alliance more relevant than ever. Russia's 2014 advances in the east with the annexation of Crimea show that the organisation still has some merit as the threat of Russian advancement is real. Furthermore, NATO is relevant in other areas due to its operations in the likes of Afghanistan and Kosovo.
Cross-continental cooperation is key One argument in defence of NATO is that it is vital that countries from both sides of the Atlantic cooperate on defence due to shared values and interests. It has been argued that the EU and the US should go their separate ways when it comes to defence, however, a Transatlantic military alliance goes deeper than geographical defence and reflects shared ideals and values that countries from both sides of the Atlantic wish to protect and promote.
Nuclear protection Another advantage of NATO is that although just three of the NATO nations (the US, UK and France) have nuclear weapons, the other countries in the alliance benefit from their deterrents as they are shielded by collective responsibility. For example, the likes of Germany and Turkey, who do not have their own nuclear weapons benefit from the deterrents of the nuclear nations due to being part of the military alliance. The USSR may be long gone but there are new nuclear powers such as North Korea which remain a threat. Disadvantages
NATO is outdated You may have heard Donald Trump argue that the organisation is "obsolete". The president has since back-tracked, having reaffirmed his commitment to the organisation alongside UK PM Theresa May when she visited Washington DC. The president's former views however are not completely unheard of, with many people calling the alliance unfit for purpose in the 21st century. Without the threat from the USSR, many argue that NATO is now irrelevant and should be put in the history books.
Most NATO countries fail to pay their fair share A strong argument in opposition to NATO's continued existence is that many countries fail to pay what they should. NATO countries are recommended to commit 2% of their GDP to their defence budgets. However, the majority of NATO nations do not meet this target, prompting criticism from Donald Trump during his election campaign. The UK and the US are some of the few countries that meet this annual target, but the majority fail to contribute, adding to the idea that the US is shouldering the biggest burden, even when proportionality is taken into account.
Europe should go it alone! One argument against NATO is that the EU should go its own way on defence and cooperate with far less reliance on the USA. There have even been recent proposals for even closer defence links within the EU, suggesting that NATO is less relevant than before and that the EU should focus on its own defence. Under NATO, the US pays the most for defence spending, but free from NATO, EU countries could place more emphasis on defence cooperation.