What ended the last depression?

The 1929 stock market crash and the "Great Depression" that followed was really only ended by the Second World War. With that in mind, why does the news in FT that:

"The government of Iceland is using the threat of a €4 bn loan from Russia in exchange for a 99-year lease on the airport at Keflavik - a former American air base - as leverage to obtain financial support from the West."

Might an economically desperate Russia try another military adventure to follow their Georgian incursion? Would an airbase in Iceland be of assistance? For what it is worth, I think any war would start in an altogether different place.