Final answer:
The capital city directly menaced by a volcano is not specified in the question, but it is likely located along the Ring of Fire, an area known for frequent volcanic activity and earthquakes. Tsunamis are a related hazard that can occur in these regions.
Step-by-step explanation:
The question refers to a unique geological threat facing a capital city due to the proximity of a volcano. The capital city in question is likely to be in close proximity to a volcano, creating a direct threat to its population and infrastructure. An example of such a scenario can be seen with the capital cities near the Ring of Fire, a path along the Pacific Ocean characterized by a high frequency of earthquakes and volcanic eruptions. While the provided clues seem to refer to multiple countries with volcanic activity, the exact capital city directly menaced by a volcano is not mentioned, and more specificity is needed to answer the question accurately.
Regarding tsunami, an underwater earthquake or volcanic eruption can trigger a giant ocean wave with great destructive power. Countries like Japan and Indonesia located along the Ring of Fire have histories of such devastating natural disasters.