Will Ukraine get 'NATO-style' security guarantees? What Article 5 means and why Zelensky wants it | Explained

NATO Secretary General Mark Rutte (R) and Ukraine President Volodymyr Zelensky - File Photo

The recent meeting between US President Donald Trump and his Russian counterpart Vladimir Putin may not have produced a ceasefire or peace agreement, but it sparked a new debate: could Ukraine receive “NATO-like” security guarantees from the United States, even without formally joining the alliance?

Trump envoy Steve Witkoff claimed that Russian President Vladimir Putin had, for the first time, signalled openness to the US offering Article 5-style protection to Ukraine. If true, this would represent a dramatic shift in the security architecture of Europe.

What is NATO?

NATO, the world’s biggest military alliance, was formed in 1949 to counter the Soviet Union’s power in Europe. It started with 12 countries, including the US, UK, France, Canada, and Italy, and has since grown to 32 members, with Finland joining in 2023 and Sweden in 2024. At its heart, NATO is a collective defence pact, meaning an attack on one member is considered an attack on all.

What is Article 5?

The cornerstone of NATO is Article 5 of its founding treaty. It states: “An armed attack against one or more of them in Europe or North America shall be considered an attack against them all … (and members will) assist the Party or Parties so attacked … including the use of armed force.”

Key points about Article 5:

• It has been invoked only once in NATO history — after the September 11, 2001 terrorist attacks on the United States.
• That invocation led NATO forces into Afghanistan, marking the alliance’s first combat mission outside Europe.

Why Ukraine isn’t in NATO?

Ukraine wants to join NATO for protection against Russia, but Moscow strongly opposes it, calling it a “red line” and even using it as a reason for the 2022 invasion.

NATO itself is also hesitant. All members must agree on new admissions, and many European countries fear that Ukraine’s entry would drag the alliance into a direct war with Russia. On top of that, NATO avoids admitting countries with ongoing border disputes, and Ukraine’s conflict with Russia makes membership even more complicated.

What would a ‘NATO-like’ security guarantee for Ukraine look like?

The US and Europe are considering a “NATO-like” deal for Ukraine that would give it protection without making it a full NATO member. Under this plan, countries like the US and some European allies could promise to defend Ukraine if Russia attacks again.

Unlike NATO’s Article 5, which is a legally binding treaty, this arrangement would likely be more political, giving countries flexibility in how they respond. It might also exclude areas already under Russian control, such as Crimea and Donbas. Still, even without full NATO membership, such a pledge could act as a strong warning to Moscow and help deter further aggression.

Why Putin’s reported concession matters

After the Alaska summit, Trump said he spoke to Putin about the possibility of a collective defence guarantee for Ukraine similar to the one in place for NATO members.

Meanwhile, he also said that Zelensky could end the three-and-a-half-year war "almost immediately, if he wants to."

"Remember how it started. No getting back Obama given Crimea (12 years ago, without a shot being fired!), and NO GOING INTO NATO BY UKRAINE. Some things never change!!!", Trump wrote on Truth Social.

The promise would be outside of the framework of the Western military alliance that Ukraine wants to join and which is seen as an existential threat by Russia.

If Putin has indeed agreed to the US extending such a guarantee, it would be a surprising reversal as Russia has previously demanded that Ukraine abandon NATO aspirations altogether.

A “NATO-like” deal could give Kyiv security assurances without provoking Moscow as much as formal NATO membership would. However, Zelensky insists that no territory can be ceded and that real guarantees must be “practical, delivering protection on land, in the air, and at sea.”

While the details remain vague and officially unconfirmed, if such a deal takes shape, it could reshape Europe’s post–Cold War security order. Ukraine would gain stronger deterrence against Russia, without being a formal NATO ally. For Washington, it could be a way for Trump to claim progress toward peace while avoiding a full US treaty commitment.