[BillyCuccio]

Nato is worthless , just a vehicle to start Third World War.

[Cronos]

Technically the first world war was the War of the Austrian succession in the 18th century with wars in Europe, North and South America and in Asia

The second world war was the Napoleonic wars - with wars in Europe, the Americas (Haiti), Africa and the Indian subcontinent

The 1914 and 1939 wars I'd consider as one continued war

NATO has prevented war during the Soviet era.