The phrase "a key power" is correct and usable in written English.
It can be used to refer to an important or influential force, entity, or capability in a specific context, such as politics, economics, or personal attributes.
Example: "In the global economy, the United States is often considered a key power due to its vast resources and technological advancements."
Alternatives: "a major force" or "an essential influence".
That snatched a key power base from the Sudairis.
Despite the establishment of democratic liberties, the armed forces remained a key power in Paraguay.
At the same time, his working relationship with the security services puts him in sync with a key power bloc behind the president, she said.
Warner has long been a key power broker in FIFA politics and his backing was seen as key to bin Hammam's hopes.
The radical Shiite cleric has never held elected office but commands thousands and has established himself as a key power broker.
The government fears it sets a precedent by jeopardising a key power – the ability to decide on the business of the House of Commons.
If Mr Poplasen, who has described Dayton as "still-born", comes to power then three years of concerted and hugely expensive efforts by the West to rebuild a stable Bosnia with a measure of ethnic co-operation will have come to nought.If his arch-rival, Mrs Plavsic, is shoved out of the way, Mr Milosevic will emerge again as a key power-broker in Bosnia.
Mr Ntaganda then joined yet another rebel group - the CNDP - under the leadership of Laurent Nkunda, a key power-broker in the east of the country who, like Gen Ntaganda, had started his military career in the Rwandan rebel force that ended the genocide.
But CdM got a key power-play goal from junior Grace Morgan to extend its lead in the fourth quarter.
But even if the law were not a tax, it still easily passes muster as an exercise of a second key power of Congress - the power to regulate interstate commerce.
But analysts say that while the new alignment reflects a renewed determination from key power brokers to resolve the conflict, it's unclear if they will get any closer to ending Syria's suffering.
