Ring of Fire
When talking about volcanoes, the fact that many of them occur at the periphery of the Pacific Plate is often mentioned. Take a look at the map of the Pacific Plate below, then look at the Google Map of volcanoes. You'll see that the Google map shows volcanoes aligned with the borders of the Pacific Plate and the minor tectonic plates along its periphery.
A good example of a minor tectonic plate is the Okhotsk microplate that covers the Kamchatka Peninsula, Sakhalin Island, and regions of northern Japan. The boundary between Okhotsk microplate and Pacific plate is a subduction zone, where the Pacific plate subducts beneath the Okhotsk Plate. The Kuril Islands are along that boundary.
graphic by Alataristarion
Geothermal Energy
Volcanoes are sources of heat, and numerous organization are now building power plants to harvest that energy. One example is WKP Gunung Sirung, that started building a geothermal power plant on Indonesia's Pantar Island.
You can get up-to-speed on global geothernal power generation from the Global Geothermal Power Tracker.
World War II and Volcanoes
Volcanoes played a part in World War II. The article, Mount Vesuvius Eruption of March 1944 has numerous photos, such as the one below, of how this eruption was disruptive to the war effort.
During WWII, the United States and its allies were at war with Japan in the Pacific. The war involved Japan capturing and trying to hold Pacific islands. The vast majority of these islands were formed by volcanoes.
In particular, the Aleutian Islands and the Kuril Islands were all formed by volcanoes. Pilots who flew patrols in PBY Catalinas and PV-1 Venturas, and bombing missions in B-24s, B-25s, and B-26s, had to be careful to not run into a tall volcano in the notorious bad weather, and low-visibility in the Aleutians.
List of Current Eruptions (Smithsonian)