Was Nato expansion to blame for the war?

Putin has for years complained about Nato’s eastward expansion as a security threat, and sees any possibility of Ukraine joining the alliance as a major red line.

Before Russia’s 2022 invasion he demanded that Nato remove multinational deployments from the Central and Eastern European states that joined the Western alliance after 1997.

But it was Russia who launched military action in Eastern Europe, when it invaded Georgia in 2008 and then Crimea in 2014.

After the Crimea invasion, Nato established a continuous presence on its eastern flank – closest to Russia.

Nato has always stressed the whole purpose of the alliance is to defend territories “with no aggressive intentions”. Sweden and Finland have joined Nato in the past two years precisely because of the perceived Russian threat.

It is part of Ukraine’s constitution to join the European Union and Nato, but there was no real prospect of this when the full-scale war began.

Zelensky said as much two weeks into the invasion: “Nato is not prepared to accept Ukraine.”

He has since said he would consider resigning in exchange for Nato membership, but Trump says Kyiv should “forget about” joining the Western alliance.

Putin has accused Nato of participating in the war, because its member states have increasingly sent Ukraine military hardware, including tanks and fighter jets, air defence systems, missile systems, artillery and drones.

Nato has provided security assistance and training to Ukraine, but it insists that does not make it a party to the war.

Putin’s grievance against Nato dates back to 1990, when he claims the West promised not to expand “an inch to the East”.

However that was before the Soviet Union collapsed and it was based on a limited commitment made to then Soviet President Mikhail Gorbachev.

Gorbachev said “the topic of Nato expansion was never discussed” at the time.

Read more: What is Nato?

Before his return to the White House and since, President Donald Trump has suggested Ukraine’s president was responsible for the war with Russia.

In reality, the war began in 2014, when Putin seized Crimea and Russian proxies grabbed part of eastern Ukraine. Zelensky had not even entered politics by then. Putin then ordered Russia’s full-scale invasion eight years later, after months of meticulous co-ordination and denials of any such plan.

But Trump’s messaging has not been altogether consistent, so it is difficult to know whether he truly believes Zelensky was to blame.

“[Zelensky] should never have let the war start, that war’s a loser,” he said in October 2024.

He repeated that theory a day after a Russian missile killed 35 people in Sumy in April 2025: “When you start a war, you got to know you can win.”

Trump has been accused of adopting Russian narratives on the war, and Zelensky has said he “lives in this disinformation space”.

However, the US president has also recognised Putin’s overall responsibility.

“Biden could have stopped it and Zelensky could have stopped it, and Putin should have never started it. Everybody is to blame,” he said.

Asked to clarify his comments days later, he told reporters days later that he was not happy with Zelensky: “I’m not blaming him, but what I am saying is that I wouldn’t say he’s done the greatest job.”

At the start of the 2022 invasion, Putin vowed to protect people in occupied areas of eastern Ukraine from eight years of Ukrainian “bullying and genocide, during the war in the east.

More than 14,000 people died on both sides of the front line between 2014-2022, but Russian claims of Ukrainian Nazis committing genocide in the occupied regions never added up, and no international body has spoken of genocide. Germany’s chancellor called the allegation “ridiculous”.

The Russian taunts of Nazis in charge in Kyiv are also not correct.

Modern Ukraine has no far-right parties in parliament – they failed to get enough votes in the 2019 elections. On top of that, Zelensky is Jewish and many of his relatives were murdered by the Nazis in World War Two.

Putin condemns him as a “disgrace to the Jewish people”, but the US Holocaust Memorial Museum rejects his claims outright, saying he “misrepresented and misappropriated Holocaust history”.

Putin himself was accused of war crimes by the International Criminal Court in 2024, although that has been rejected by the Kremlin.