It is...a contributing factor. But mostly, almost every country in the world has an organization like that. You might purport to be allies with one country but that does not mean you are not sending in people to gather information.

[ if you were caught, you would cause an incident so you just had to be good enough to not be caught. ]

But the wars were a major factor. What better way to weaken someone than via direct physical confrontation via the military and via espionage as well?