NATO is launching its biggest military exercise in 13 years, involving 36,000 military personnel from more than 30 countries.
NATO Deputy Secretary-General Alexander Vershbow said the Trident Juncture exercise will demonstrate that NATO "can deal with everything from conventional military engagements to more subtle hybrid warfare techniques and propaganda."
Vershbow was speaking at the opening ceremony in the Sicilian city of Trapani on October 19.
Vershbow said the geopolitical situation is now much more unstable than it was when the last such large-scale exercises were held during the Cold War.
He cited Russia's annexation of Crimea, support of separatists in eastern Ukraine and attacks against moderate rebels in Syria, as well as the infiltration of terror groups into Libya and Syria.
Trapani will serve as the operational center for the exercise that begins on October 21 and runs through early November, extending into Spain, Portugal and adjacent waters.
The exercise envisions a fictitious invasion by a large country of a small alliance member.
Vershbow denied that the fictitious aggressor was Russia.