12 to 32

Just 12 founding member countries signed the North Atlantic Treaty back in 1949 as the United States, Canada and much of western Europe clubbed together to face up to the threat of former World War II ally the Soviet Union.

As the alliance’s first Secretary General Lord Ismay quipped, NATO’s purpose was to “keep the Soviet Union out, the Americans in, and the Germans down”.

In 1952, often uncomfortable bedfellows Turkey and Greece joined, before West Germany became a member three years later.

After the end of the Cold War, NATO went through several waves of eastwards enlargement that saw its border with Russia grow with the inclusion of Poland and the former Soviet Baltic states.

After Moscow invaded Ukraine in 2022, Nordic neighbors Sweden and Finland reversed long-standing policies of non-alignment - taking the alliance to 32 members.

In total, NATO countries account for close to one billion people and around 50 percent of the world’s GDP.

Together they have 3.2 million men and women serving in their militaries.

Iceland is the only member without its own army.

One

NATO has only ever once triggered its Article Five collective-defense clause --- which says an attack on one member is considered an attack on all -- after the 9/11 attack on the US in 2001.

That decision was a show of support for the alliance’s leading military power and far different from the threat in Europe originally foreseen by its founders.

The fall-out from 9/11 saw NATO get involved in Afghanistan where it remained until 2021, when a calamitous US-led withdrawal allowed the Taliban to take back power.

Two percent

In response to Russia’s seizure of Crimea from Ukraine in 2014, NATO allies agreed they would aim to spend two percent of their GDPs on defense.

That goal was raised after Moscow launched its all-out invasion of its neighbor in 2022 to having two percent as a minimum.

Former US president Donald Trump has railed against NATO countries not spending enough, warning he would encourage Russia to “do whatever the hell they want” to those not meeting their obligations.

In 2024, 20 NATO members are expected to reach two percent, up from just three in 2014.

25

June 2024 will mark 25 years since NATO deployed troops in Kosovo in 1999, completing the withdrawal of Serbian forces after its 77-day air campaign.

That military intervention was just the second in NATO’s history, following its involvement in Bosnia in the mid-1990s.

A quarter of a century on, NATO’s Kosovo Force (KFOR) still remains on the ground in the Balkans, making it the alliance’s longest-running mission.

After a rise in tensions last year led to rioting that wounded 93 NATO troops, allies agreed to send 1,000 additional soldiers to KFOR -- taking its total to around 4,500.

Beyond the Balkans, NATO’s other major overseas missions have included its nearly two decades in Afghanistan and the 2011 bombing campaign in Libya.

43

No country has ever withdrawn from NATO, but France spent almost 43 years outside its military command structure after President Charles de Gaulle pulled out in 1966 in protest at US domination.

The decision -- which saw NATO move its headquarters from Paris to Brussels -- was only reversed by President Nicolas Sarkozy in 2009.

Nonetheless, France’s sometimes strained relationship with NATO continues -- and in 2019 President Emmanuel Macron accused the alliance of suffering “brain death.”

Macron later said Russia’s 2022 invasion of Ukraine had woken up NATO with the “worst of electroshocks.”