The former US president, who is expected to win the Republican nomination for the 2024 presidential election, even said he'd "encourage" Russia to "do whatever the hell they want" to those nations, which sent shudders across parts of Europe.
Nato Secretary-General Jens Stoltenberg suggested his "unhinged" remarks, made at a campaign rally in South Carolina on Saturday, puts both American and European soldiers' lives at risk. He reiterated that "any attack on Nato will be met with a united and forceful response".
This isn't the first time Trump has expressed a lack of commitment and support to the Western defence alliance, but his suggestion he would welcome a Russian attack has raised concerns even further, particularly among many Eastern European states neighbouring Ukraine.
One Republican senator suggested Trump was “simply ringing the warning bell” to show that Nato countries aren't prepared enough militarily, but Trump's comments have prompted renewed debate about the future of the alliance. In some ways, they've also brought European members closer together, with German chancellor Olaf Scholz telling a conference in Berlin that Nato's "promise of protection applies unreservedly — all for one, one for all".
Donald Trump: Speaking at a campaign rally in South Carolina on Saturday, Trump recalled a conversation he had with "one of the presidents of a big country". He said this leader asked what would happen "if we don't pay and we're attacked by Russia", to which Trump said "No, I would not protect you. In fact, I would encourage them to do whatever the hell they want".
Jens Stoltenberg: Nato's general secretary was quick to say that an attack on any of the alliance's members "will be met with a united and forceful response". He added that he expects the US to remain "a strong and devoted ally of Nato, whoever wins the presidential election".
Olaf Scholz: During a joint press conference in Berlin with Polish prime minister Donald Tusk, German chancellor Olaf Scholz said any "relativisation" of Nato's guarantee of mutual defence is dangerous and is "solely in Russia's interests". He added that the alliance's guarantee of mutual defence applies "unreservedly".
Why it matters
With the war in Europe showing no signs of ending, some have suggested Trump's remarks could embolden Russian president Vladimir Putin in his assault on Ukraine, or even a future attack elsewhere in the continent.
The Kremlin remained tight-lipped when asked about Trump's comments, with a spokesperson telling reporters: "I am still Putin's press secretary, but not Trump's."
While Moscow would be expected to hold their cards close to their chests in situations like this, the head of Estonia's Foreign Intelligence Service delivered a chilling warning on Tuesday. Kaupo Rosin told reporters: "Russia has chosen a path which is a long-term confrontation ... and the Kremlin is probably anticipating a possible conflict with Nato within the next decade or so."
He added that a military attack is "highly unlikely" in the short term, partly because Russia has to keep troops in Ukraine, and would remain unlikely if Russian build-up of forces was matched in Europe.
Trump's comments stem from a commitment among Nato members that each spends 2% of GDP on defence spending to "continue to ensure the Alliance's military readiness". This, according to Nato, serves as an "indicator of a country's political will" to contribute to Nato's defence efforts. The US reportedly spends a significant amount (3.49%) on defence, higher than every Nato country bar Poland.
Nonetheless, Article 5 of the North Atlantic Treaty enshrines the principle of collective defence among its members. In other words, it means that an attack on one member is treated as an attack on all. This is one of the key reason for Nato's existence, so a potential leader of its most powerful member disregarding Article 5 has naturally caused alarm.
"Europe has to get its act together... This is a matter of answering a question about what will happen if Trump wins. We don't have time. We must have bigger defence industry capacity," a Polish government source said.
What are the key people saying?
You gotta pay your bills: "One of the presidents of a big country stood up and said, ‘Well sir, if we don’t pay and we’re attacked by Russia, will you protect us?’ I said, ‘You didn’t pay? You’re delinquent?’ He said, ‘Yes, let’s say that happened.’ No, I would not protect you. In fact, I would encourage them to do whatever the hell they want. You gotta pay. You gotta pay your bills." - Donald Trump, speaking at a campaign rally on Saturday 10 February
Trump is putting lives at risk "Any suggestion that allies will not defend each other undermines all of our security, including that of the US, and puts American and European soldiers at increased risk. Any attack on NATO will be met with a united and forceful response." - Nato Secretary General Jens Stoltenberg on Sunday 11 February
No one should play with Europe's security: "Any relativisation of NATO's guarantee of assistance is irresponsible and dangerous. It is solely in Russia's interests. Nobody should play around or trade with Europe's security - German chancellor Olaf Scholz at a conference in Berlin on Monday 12 February
What are others saying?
All for one, and one for all: "There is no alternative to the EU, Nato, transatlantic cooperation. Europe must become a safe continent, and this means that the European Union, France and Poland must become strong and ready to defend their own borders and to defend and support our allies and friends from outside the Union. It is probably here in Paris that the words from 'The Three Musketeers' by Alexandre Dumas resonate most clearly: 'All for one, and one for all'." - Polish prime minister Donald Tusk at a conference in Paris on Monday
Appalling and dangerous: "Donald Trump's admission that he intends to give Putin a green light for more war and violence, to continue his brutal assault against a free Ukraine, and to expand his aggression to the people of Poland and the Baltic States are appalling and dangerous," - US president Joe Biden in a statement on Sunday 11 February
Trump is ringing the warning bell: "Nato countries that don’t spend enough on defence, like Germany, are already encouraging Russian aggression and President Trump is simply ringing the warning bell. Strength, not weakness, deters aggression. Russia invaded Ukraine twice under Barack Obama and Joe Biden, but not under Donald Trump.” - Rep Senator Tom Cotton of Arkansas to the New York Times
Europe needs a plan with our without the US: "It is hard to believe that Trump would actually disband Nato, as he has reportedly privately threatened to do. But the alliance’s Article 5, its pledge to go to war if any member’s integrity is threatened, is looking in need of reconsideration." - Simon Jenkins in the Guardian
Trump's remarks are not a sensible approach: “I am a very strong supporter of Nato. It is what helps to keep us safe and that is so essential in this world where we have seen Putin’s terrible illegal invasion of Ukraine. And actually Nato this year has got stronger, with Sweden and Finland joining. Of course we want all countries, like us, to spend 2% (of GDP), but I think what was said was not a sensible approach." - UK foreign secretary David Cameron speaking to reporters on Monday 12 February
Nato could become stronger thanks to Trump: "The trouble with Trump’s remarks about Putin, however, are that they do not amount to an idle threat; rather they are an invitation to a villain who doesn’t need much in the way of encouragement. That is an argument for saying that Trump really has overstepped the mark this time and put Europe in peril. But if his remarks do as intended and quickly jolt recalcitrant Nato members into action to beef up their defences then hopefully the end result might be to make Putin less inclined to strike. Not for the first time, Trump’s sheer unpredictability may prove to have its uses." - Ross Clark for the Spectator
Either Nato exists, or it doesn't: "Let’s be serious. Nato cannot be an 'à la carte' military alliance. Nato cannot be an alliance that works depending on the 'humeur' of the president of the United States in those days. It is not 'Now yes. Tomorrow, no. It depends, who are you?'. No, come on, let’s be serious. NATO cannot be an alliance 'à la carte'. It exists, or it does not exist. But I am not going to spend my time commenting on any silly idea that comes during this electoral campaign in the United States" - High Representative of the European Union for Foreign Affairs and Security Policy, Josep Borrell on Monday, 12 February