Estonia (in fact all the 3 Baltic States) under-taxes at present in a way that’s not sustainable. For example there is a significant NATO presence there to protect them from the Russians. At some point someone will want them to make a fair contribution to that, such as purchasing a few tanks and fighter jets...
According to NATO's 2018 report, Estonia was one of only six NATO countries (out of 29) that met the goal of dedicating 2% of their GDP to defense. Not that dedicating 100% would stop Russia if they wanted to invade.
As the current American President has shown, treaties and obligations only go so far. That destruction of trust may be the most lasting damage that he causes.