"a drastic action" is a perfectly correct and usable phrase in written English.
You can use it when you want to describe a situation or event where a significant or sudden change has taken effect. For example, "The president's decision to close the borders was a drastic action, but it was necessary to stop the spread of the virus."
Why did the erstwhile even-tempered Ewing take such a drastic action?
Such a drastic action would have been subject to challenge as "arbitrary and capricious" under the Administrative Procedure Act, leading to perhaps years of litigation.
The Military Commissions Act, the lawyers maintain, amounted to a "suspension" of habeas corpus without meeting the conditions set by the Constitution for such a drastic action.
And in a drastic action, unprecedented in the five-year-saga of euro zone bank bailouts, the Dutch finance minister decreed: Bondholders like Mr. Zannakis would be wiped out.
BERLIN — Even as showrooms in Europe prepare for the arrival of 2014 vehicles, authorities in France have sparked controversy with a drastic action: blocking the registration — effectively shutting down sales — of some popular new Mercedes-Benz cars, including the A-Class, B-Class, CLA and SL models.
But Tomas Sedlacek, once an adviser to former President Vaclav Havel and an outspoken critic of Mr. Klaus, said that even if the complaint was filed — and it was unclear senators would be willing to take such a drastic action — it would largely be a symbolic gesture.
But they also say that being chosen for the 2008 Games could put a brake on any drastic action.
Deleting your Facebook account permanently is a rather drastic action.
Yet the place is invariably presented as a failure needing drastic action.
It's drastic action, a last resort, and a decision that has not been taken lightly, but I'm heartened to see us all standing united.
James Franco is surely due a best actor nod for his role as a climber forced to take drastic action after his arm becomes trapped by a falling rock.
