What counts as "visiting a country", anyway?

Here&rsquo;s something we argue about. What constitutes &lsquo;visiting&rsquo; a country? Do you have to leave the airport? Stay overnight? Or what. I think we&rsquo;d all agree that just flying over a country doesn&rsquo;t count, you at least have to LAND. But what if you&rsquo;re only in the airport? I am firmly on the side of &ldquo;Landing at the airport counts, because you are on the ground…