According to the Institute for the Study of War (ISW), Russia's sabotage and espionage activities may indicate preparations for a war with NATO sooner than intelligence predicts.
Russia's constant drone sabotage and espionage against military bases and facilities in Europe pose a significant threat to the Alliance. Analysts at ISW believe that Russia's long-range weapons and advanced drone production are a direct threat to NATO.
The Russian Federation is actively building new military forces and creating a strategic reserve of personnel, which can be used in both Ukraine and a possible war against NATO. This capability shows that Russia can rebuild its human resources despite heavy losses.
Russia could become a real threat to NATO before 2036.
Author's summary: Russia's preparations may pose an earlier threat to NATO.