The phrase "a radical declaration" is correct and usable in written English.
It can be used to describe a statement or announcement that is extreme or significantly different from the norm, often in a political or social context.
Example: "The activist made a radical declaration about the need for immediate climate action, urging everyone to reconsider their lifestyle choices."
Alternatives: "an extreme statement" or "a bold announcement".
"I don't think it's very exciting anymore for customers to come into a store and just see clothes," said Robert Burke, the fashion director of Bergdorf Goodman, on Monday, a radical declaration, given that selling clothes is the basis for Mr. Burke's paycheck.
Organized so that no one man could dominate it, the group espoused a radical declaration of principles (authored by Trotter and Du Bois), calling for agitation for equal economic opportunity and exercise of full civil rights for African Americans.
"We won't rob middle-class Peter to pay working class Paul" is their pledge, a truly radical declaration, since the tax and benefit system taken together are highly redistributive.
Politically, the clerical body which is the spiritual point of reference for mainstream militant Sunni groups, the Association of Muslim Clerics (AMC), has put out a statement which clearly takes issue with the radical declaration put out by the ISIS spokesman, Abu Muhammad al-Adnani, the day before.
The nations will take your message as a declaration of war and a radical threat to their own sovereignty.
That was what Ms. Pearson considered the happy ending 10 years ago, and it was still rather radical, a declaration that women could just walk away from a structure that did not work for them.
Jefferson, architect of the Declaration of Independence, was to Federalists a radical atheist, a levelling democrat sworn to overthrow - by violence if necessary - all order, both divine and human.
But soon he embarked on a new discussion, about whether the Declaration of Independence was a conservative or a radical document.
In the reprise, the song goes though a radical shift in point of view and is more a declaration of love that is strengthening.
The punchline of this declaration of surrender is that it was signed by a radical leftist rebel, who stepped up with the aim of mobilising the whole of Europe against the German chancellor's austerity diktats.
Whether Mr. Steel's decision last year to abandon Lincoln Center and turn City Opera into an itinerant company is seen as a declaration of independence or an act of desperation, it represented a radical departure from what the company had always been.
