Sure, but the effectiveness will be less if the "problem" is global. If the US has 50% of the worlds demand for some good, and only the US fights inflation, the

Sure, but the effectiveness will be less if the "problem" is global. If the US has 50% of the worlds demand for some good, and only the US fights inflation, then the effectiveness of the measures taken will only be 50%. So for the US maybe that is still possible, but if you are Costa Rica that becomes meaningless.