Why 192? Because this is the up-to-date number of plausibly sovereign nations in the world. Dependent territories, regions and colonies will not count. There is no room for Gibraltar here, or Greenland, or the Falkland Islands, or, indeed, Scotland or Wales.
Some of the countries on (or off) the list remain a matter of contention. The UN, in fact, has only 185 members, though some of the absentees are simply people who have never felt inclined to apply: Switzerland, for example.
There is also no room in the UN for two Chinas, but for our purposes, Taiwan seems sufficiently sovereign and country-like to deserve inclusion. The same cannot yet be said for places such as Kurdistan, Palestine and the Basque Country, though countries of such dubious sovereignty as Andorra, San Marino and Monaco do manage to sneak aboard.
And putting aside the whole issue of countries unexpectedly changing their names (Congo for Zaire, Myanmar for Burma, etc), another worrying consideration is the possibility of countries coming in and out of existence during the lifetime of the series.
The current decade has produced at least 20 brand new countries, including 15 former Soviet republics, at least four former Yugoslav republics, not to mention sundry other countries such as Slovakia and Eritrea. Meanwhile the USSR, East Germany and South Yemen have been shown the door.
The coming decade is unlikely to be so fruitful in terms of new members for the UN. The possibilities? Western Sahara and East Timor might both get lucky. Bermuda might finally decide that it is ready to take the plunge. St Kitts and Nevis might implement their discussed separation. Perhaps even Scotland will achieve its independence.
Meanwhile, we will plod from week to week, discovering unexpected patterns in alphabetic tourism, such as that four out of the first five countries in the list (Afghanistan, Albania, Algeria and Angola) are also four of the most dangerous. Or that of the nine countries beginning with L (Laos, Latvia, Lebanon, Lesotho, Liberia, Libya, Liechtenstein, Lithuania and Luxembourg), not one has a population of more than five million. Or that, among the Is, Iran and Iraq are only separated from Israel by Ireland. Or that no fewer than 23 countries - 12 per cent - begin their names with S.
Spooky coincidences? Or signs of a Greater Intelligence? I am reserving judgment until I have worked out where and what the Republic of Palau is.