In the war game, he gets straight to the point, Article 42.7.

This clause does not trigger an automatic military response.

It does, however, require concrete and effective assistance.

That assistance can take many forms: intelligence, military, political, or economic.

But precisely because of that, it is also easier to invoke.

Ultimately, however, it is up to the country under attack to invoke the clause.

The other member states then decide on the nature and extent of the assistance they provide.