It looks like the threat of competitive increases in trade tariffs has vanished, at least for the moment, as economies are getting back in shape. This episode highlighted how tariffs are part of a prisoner's dilemma: increasing tariffs is good for you, at least in the short term, as it gives more market share to local firms and/or more revenue to the state. But it hurts the foreign country, and if everybody does it, joint welfare is reduced because of the lower gains from exchange, the misallocation of productive resources and the loss of competitiveness of protected industries. It is precisely because of this prisoner's dilemma that the GATT (General Agreement on Tariffs and Trade) and then the WTO (World Trade Organization) were put in place.
Renee Bowen takes this reasoning further by looking a at a multilateral prisoner's dilemma, and interestingly the optimal institution that emerges looks very much like WTO's dispute settlement mechanism, in that countries cannot retaliate while a dispute is being settled. The key is that once a large enough number of countries participate in the WTO, the threat of sanctions is sufficient to obtain settlement and nobody is compelled to jump the gun with retaliations.