To understand Iran, you must begin by understanding how large it is. Iran is the 17th largest country in world. It measures 1,684,000 square kilometers. That means that its territory is larger than the combined territories of France, Germany, the Netherlands, Belgium, Spain and Portugal - Western Europe. Iran is the 16th most populous country in the world, with about 70 million people. Its population is larger than the populations of either France or the United Kingdom.
Under the current circumstances, it might be useful to benchmark Iran against Iraq or Afghanistan. Iraq is 433,000 square kilometers, with about 25 million people, so Iran is roughly four times as large and three times as populous. Afghanistan is about 652,000 square kilometers, with a population of about 30 million. One way to look at it is that Iran is 68 percent larger than Iraq and Afghanistan combined, with 40 percent more population.
More important are its topographical barriers. Iran is defined, above all, by its mountains, which form its frontiers, enfold its cities and describe its historical heartland. To understand Iran, you must understand not only how large it is but also how mountainous it is.