Recent rhetoric from US President Donald Trump, including discussion of potential tariffs and even “ownership” of Greenland, has prompted a reassessment of European defense strategies. In Brussels, officials have debated whether the United States would continue to uphold Article 5 of the North Atlantic Treaty Organization (NATO), which stipulates that an attack on one member state is considered an attack on all.
Alongside NATO’s collective defense pledge, a lesser-known commitment exists within the European Union. Article 42.7 of the EU obligates member states to provide aid “by all the means in their power” should another EU country come under attack.
What is the EU’s Article 42.7 and how does it differ from NATO’s Article 5?
Introduced in 2009 with the Lisbon Treaty, Article 42.7 states that if a member state experiences armed aggression on its territory, other member states are obligated to provide assistance “by all the means in their power.”
The article acknowledges that this obligation “shall not prejudice the specific character of the security and defense policy of certain member states,” recognizing that some countries’ defense commitments are primarily shaped by NATO.
Security and defense policy analyst Juraj Majcin explained that the key difference between the EU and NATO mutual defense clauses lies in how support is delivered. Even as the EU provision relies on intergovernmental and bilateral assistance, NATO’s collective defense reflects a broader, more structural deterrence principle.
Former German MP Kristian Klinck believes the EU’s Article 42.7 is more compelling than NATO’s Article 5, at least on paper. The requirement to provide help “by all means in their power” is widely interpreted as meaning “to the end of one’s strength.”
In contrast, Article 5 allows NATO nations more national discretion, permitting each country to take “such action as it deems necessary, including the employ of armed force.”
Both experts noted that assistance under Article 42.7 isn’t limited to military support, but can also include diplomacy, humanitarian aid and financial backing. This could be particularly relevant to non-aligned EU members Austria, Cyprus, Ireland, and Malta, who traditionally avoid formal military alliances.
Has either defense clause ever been tested?
NATO’s Article 5 was activated once, after the 9/11 attacks in 2001, leading to the deployment of surveillance aircraft to patrol US airspace. A total of 830 crew members from 13 NATO countries flew over 360 missions.
The EU’s Article 42.7 has also been invoked only once, in response to terrorism following the ISIS-led attacks in Paris in 2015. Germany and other EU members supported French forces with naval and air assets, largely as part of a US-led coalition.
Security analyst Majcin cautioned that in both instances, the collective defense clauses were applied to events “they were not designed for.” Klinck agreed, noting that France faced a terrorist attack in 2015, but not a major military attack, and that Article 42.7 remains largely untested.
Would EU states really defend each other?
Since Russia’s invasion of Ukraine in 2022, many EU states have increased defense spending and integrated their military systems. Klinck believes Europe still has function to do to build up defense capabilities, but points to progress, such as the full integration of Dutch and German land forces and naval cooperation between the Netherlands and Belgium.
“If we can keep up this work and act in the spirit shown by European leaders in Davos when they reacted to Trump’s comments on Greenland we are up to the task,” Klinck added.
NATO Secretary General Mark Rutte recently stated, “If anyone thinks here again that the European Union, or Europe as a whole, can defend itself without the US, keep on dreaming.”
Majcin agrees, stating that when considering Europe’s capacity to defend itself without the United States, it’s important to consider not only a large-scale attack like in Ukraine, but also Russia’s goal to undermine NATO politically.
Frequently Asked Questions
What is Article 42.7 of the European Union?
Article 42.7 of the Lisbon Treaty obligates EU member states to provide aid “by all the means in their power” if another EU country is the victim of armed aggression on its territory.
How does the EU’s Article 42.7 differ from NATO’s Article 5?
The EU provision is largely based on intergovernmental and bilateral assistance, while NATO’s collective defense reflects a broader, more structural deterrence principle.
Has either defense clause ever been activated?
NATO’s Article 5 was activated after the 9/11 attacks in 2001, and the EU’s Article 42.7 was invoked following the ISIS-led attacks in Paris in 2015.
As European nations navigate shifting geopolitical landscapes and reassess their security commitments, will the pledges of mutual defense outlined in Article 42.7 prove sufficient to ensure collective security in the years to come?
