The phrase "a forceful ally" is correct and usable in written English.
It can be used to describe someone or something that is a strong and influential supporter in a particular context, such as politics, business, or personal relationships.
Example: "In the negotiations, she proved to be a forceful ally, advocating passionately for our interests."
Alternatives: "a powerful supporter" or "a strong advocate".
Carol Moseley Braun, a forceful ally with a strong record, is getting women's issues onto the table and into the political debate, and she deserves our support.
But having been a forceful ally of President Bill Clinton in the Kosovo war and having intervened successfully in Sierra Leone in 2000, Mr. Blair was a believer in using force to impose a more rational world order, and after the attacks on the United States on Sept. 11, 2001, he was quick to align himself with Mr. Bush.
Having served side by side with Mark, we know we can always count on him to be a forceful ally for economic justice, reproductive rights and healthcare, and more.
In a country that had always relied on force and the threat of force as pivotal to public life, Yeltsin had jettisoned his most forceful ally.
After the victory of the Fidel Castro revolution in Cuba in 1959, Cárdenas became the most forceful ally of the Cuban revolutionaries in Mexico.
They say that the carriers, by testing this technology, integrating it into their phones and putting their marketing muscle behind it, could be forceful allies in a fight to help people resist what they say is the compulsive lure of mobile devices.
"Joe Bruno has been a forceful and thoughtful ally on health care issues when hospitals and nursing homes and home care workers have been threatened," he said, adding, "our support for him is as strong as it has ever been".
Apparently appalled by the way "containment" had turned out, he became a forceful advocate of superpower disengagement allied to progressive disarmament.
"We want to bring back political competition that will create a competitive economy," says Yevgeny Roizman, who, in addition to being a political ally, is also a forceful advocate for drug rehab centers.
To discredit allegations of war crimes, Syria and its ally Russia have instigated a forceful campaign of disinformation and punditry.
While her husband controlled the secret police and special forces, Madame Nhu acted as a forceful counterweight to the diffident president, badgering Diem's aides, allies and critics with unwelcome advice, public threats and subtle manipulations.
