1. Skip to content
  2. Skip to main menu
  3. Skip to more DW sites

What are NATO Articles 4 and 5?

November 15, 2022

After reports of a missile strike in Poland, there had been speculation the Polish government might invoke Article 4 of the NATO treaty.

NATO Secretary General Jens Stoltenberg looks down, concerned
NATO officials are likely to meet in Brussels on Wednesday morning to discuss Article 4 Image: Kenzo Tribouillard/AFP

Article 4 of the NATO treaty covers the case when a member state feels threatened by another country or a terrorist organization. The 30 member states then start formal consultations at the request of the threatened member. The talks look at whether a threat exists and how to counter it, with decisions arrived at unanimously.

Article 4 does not, however, mean that there will be direct pressure to act.

This consultation mechanism has been triggered several times in NATO's history. For instance, by Turkey one year ago, when Turkish soldiers were killed in an attack from Syria. At that time, NATO decided to consult, but did not take any action.

Chechens fighting for and against Russia in Ukraine

How does NATO Article 4 differ from Article 5?

Following Russia's invasion of Ukraine in late February, NATO members Estonia, Latvia, Lithuania and Poland triggered Article 4. Along with Slovakia, Hungary and Romania, those countries are part of the "eastern flank" of NATO, which has been reinforced with thousands of troops from NATO members. 

Article 4 is different from Article 5 of the NATO Charter. The latter lays out the military assistance by the entire alliance, should one of the member states get attacked. The only time that Article 5 was used was in 2001 after the al-Qaeda attacks on the US, which killed more than 3,000 people. They became known as the 9/11 attacks. When the US then attacked Afghanistan, NATO sent a mission alongside.

The NATO treaty only applies to member states. Given that Ukraine is not part of the alliance, it can trigger neither Article 4 nor 5.

This article was originally published in German

Riegert Bernd Kommentarbild App
Bernd Riegert Senior European correspondent in Brussels with a focus on people and politics in the European Union
Skip next section Explore more
Skip next section DW's Top Story

DW's Top Story

President Volodymyr Zelenskyy in a video address in early June
Skip next section More stories from DW
Go to homepage