Praxis

Praxis was a the only moon of the Klingon homeworld, Qo'noS.
An inhabited moon, it was used as the Klingon Empire's key energy-production facility in the 23rd century.

In 2293, Praxis was famously destroyed in a large explosion caused by over-mining and insufficient safety precautions.

The explosion caused a powerful subspace shock wave, along with deadly pollution of Qo'noS' ozone, threatening the depletion of the oxygen in that planet's atmosphere within approximately fifty Earth years.

When Starfleet offered assistance, the Klingons ordered them to obey treaty stipulations, and remain outside the Neutral Zone.

Praxis' destruction resulted in significant political change, as the Empire had to divert resources from their vast military budget to address the environmental change.

The Chancellor at the time realized that they could not afford to continue hostilities with the United Federation of Planets, and approached the Federation with an overture of peace.

This set into motion a series of events, eventually resulting in a lasting peace between the Federation and the Empire through the Khitomer Accords.