The tip for reinforcement says "Click on the country to reinforce from and then click on the country to reinforce to"
This would only work if a From and a To are not pre-selected when we enter reinforce. But they are pre-selected, so it does not work as in the tip. When I first click the country to reinforce from, it does not move the source to the country I clicked. It only moves the destination to that country, even though it is my first click.
Also there must be a provision that after clicking the source country, if I have clicked wrongly, I may be able to select another source country by clicking again. But if the second click selects a destination country, then I am never able to select a new source. The only way this is possible is to first right-click for source country (any number of times) and then left-click for destination country (any number of times). As a short-cut, if there is no pre-selection at all, then the very first click can select the source country.