Russia, China and other countries including Iran have been testing settled states' tolerances in the West for different forms of aggression, according to a survey by the International Institute for Strategic Studies (IISS).
The engaged persistent 'tolerance warfare' has included proxy wars to cyber attacks, the report says.
Dr John Chipman, IISS Director-General, says:
"Tolerance warfare is the effort to push back lines of resistance, probe weaknesses, assert rights unilaterally, break rules, establish new facts on the ground, strip others of initiative and gain systematic advantage over hesitant opponents.
"It particularly exploits weaknesses in Western democracies whose instincts for statecraft have been tempered by geopolitical failure abroad and constraints imposed by domestic opinion on hard-power international deployment."
"Western societies in the future will need to give as much attention to tolerance warfare as they did to unwinding terrorist networks over the last decade – it is becoming a favoured strategy for those countries that cannot easily challenge their biggest rivals symmetrically," Dr John Chipman continues.
"Most obviously, President Vladimir Putin’s Russia is seeking asymmetrically to gain an advantage in its weakened position by regular use of tolerance-warfare stratagems."
Russia’s tolerance-warfare tactics are being conducted primarily in Europe and North America, and according to the IISS include:
China is also engaged in tolerance warfare, most prominently in the South China Sea, with steady encroachments on islands, reefs and other geographical features it considers its own.