Early this fall, Germany's leader Friedrich Merz assured a group of reporters in Duesseldorf that his country was "not at war."

Merz was speaking about what he characterized as Russia's repeated attempts to undermine European unity over its response to Moscow's war in Ukraine. "But we are no longer at peace either," he added.

Germany's chancellor did not mention World War III or even imply it would soon be underway. But he did tap into a growing sense of apprehension among some Europeans and Americans: surveys show that many of them no longer view a global war as a remote prospect and believe it could occur in the next five to ten years.

Robert Muggah, the founder of SecDev, an Ottawa, Canada-based security and intelligence think tank, said that there is no shortage of signals and overlapping crises to point to that, to a degree, suggest there already is a "global war being fought across multiple domains without ever being formally announced."

Putin, Ukraine, long-range missiles: Why there's talk about WWIII