Here's why:

* Arid and semi-arid: Most of the country experiences low rainfall, making it dry and susceptible to droughts. This aligns with a desert climate.

* Alpine: The mountainous terrain of Afghanistan, with the Hindu Kush range dominating the north, creates distinct alpine zones at higher elevations. These areas experience colder temperatures, snow, and unique plant and animal life.

* Desert: The flat plains in the south and west are characteristic of a desert environment, experiencing high temperatures, low humidity, and sparse vegetation.

It's important to note:

* The climate varies significantly across the country.

* The northern mountainous regions are colder than the southern plains.

* The climate is influenced by both the elevation and distance from the ocean.

Therefore, while a single classification is difficult, Afghanistan's climate is a complex mixture of desert, alpine, and arid characteristics.