Joking aside, those countries have a very sensible policy. While multi-citizenship may offer some benefits, it also results in numerous problems, too. We see t

Joking aside, those countries have a very sensible policy. While multi-citizenship may offer some benefits, it also results in numerous problems, too. We see these problems in Canada far too often, for example. One issue is the Canadian-of-convenience problem. This involves people who have Canadian citizenship and some other citizenship, but spend all of their time outside of Canada, often for years or even decades at a time. Despite having no real ties to Canada, and despite not paying Canadian taxes, these individuals will flee back to Canada, possibly at the expense of Canadian taxpayers, if they face difficulties (such as a war breaking out) in the foreign nation where they actually live. The opposite of that can happen, too, where foreign citizenship might be used to help somebody avoid criminal prosecution for crimes they committed in Canada. Birth tourism is another problem. Multiple citizenship also exposes people in Canada to a greater risk of foreign influence and foreign interference. This is especially true for politicians, and it certainly raises questions about where their loyalty may rest. It also results in disruption in Canada due to foreign conflicts or disagreements (often ones that are happening on literally the opposite side of the world and don't otherwise involve Canada in any way) spilling over into Canada. Pretty much every international conflict leads to disruptive protests in Canada's major cities, for example. Sometimes these foreign issues can even start affecting Canadian elections. With maybe the exception of Canadian-US dual citizenship, due to the proximity and close ties between the two nations, Canada should do away with multi-citizenship completely.