Yes. This provision was not very clearly written (at least not in the English language version) so its not obvious whether this provision applies to non-nuclear

Yes. This provision was not very clearly written (at least not in the English language version) so its not obvious whether this provision applies to non-nuclear aggression against Ukraine. The scope of the qualifier "in which nuclear weapons are used" is ambiguous. But in any case, the only required response is "to seek immediate United Nations Security Council action to provide assistance to Ukraine," which certainly has happened.