4 Countries that include tundra

The tundra is a treeless polar desert found in the high latitudes in the polar regions, primarily in Alaska, Canada, Russia, Greenland, Iceland, and Scandinavia, as well as sub-Antarctic islands.

Alaska, Canada, Russia, Greenland

Explanation:

The tundra consists of large areas of flat or undulating terrain without trees, above the taiga in the polar zones (Arctic tundra; it covers about 10% of the Earth's surface) or on high mountains (alpine tundra).

It is characterized by bare ground or rocks, and vegetation such as moss, lichens, small plants, and low shrubs. The vegetation of the tundra is poor but very resistant to the harsh climate. Aquatic plants germinate and bear fruit in a very short period of time, and insects also complete their life cycle very quickly, so there is an abundance of food in the tundra.

doctrine that the us had the right to expand throughout north america.