Country Definition

What is a country, and how is a country defined? When people ask how many countries there are in the world, they expect a simple answer. After [blank] , we've explored the whole planet, we have international travel, satellite navigation, and plenty of global organizations like the United Nations, so we [blank] really know how many countries there are! However, the answer to the question varies according to whom you ask. Most people say there are 192 countries, but others point out that there could be more like 260 of them. So why isn't there a straightforward answer? The problem [blank] because there isn't a universally agreed definition of 'country' and because, for political reasons, some countries [blank] it convenient to recognize or not recognize other countries.