"subtle attack" is a grammatically correct and usable phrase in written English.
It is typically used to describe a type of criticism or aggression that is not obvious or direct, but instead is more indirect or insidious. Example: "Her words may seem innocent, but I sense a subtle attack on my character in every sentence."
Naidu shed Gandhi's subtle attack on the book – that it distorted a true picture of Indian society by exaggeration and selection – in favour of blank denial.
MOREOVER, the experience of riding on a bus is a subtle attack against urban anonymity, the sense of being crowded in but ultimately alone.
The only thing that amazed me when it started this time round was how open it was, it used to be a subtle attack, but now it's very direct".
During a speech at a booksellers' convention in Chicago this month, Mr. Clinton demonstrated his deft hand at turning discussions of his memoirs into a subtle attack on President Bush.
"The subtle or not so subtle attack on Schundler for being extreme didn't really grab much traction in the primary campaign," said Richard A. Harris, a professor of political science at Rutgers-Camden.
It didn't take long, though, for discrete fiefs of ache and twinge to make themselves known: catheter burn (complemented by the occasional bladder spasm), sore and swollen testicles and the subtle attack of hospital-bed back.
In public for the most part, Mr. Lazio toned down the subtle attacks he had sprinkled in his convention speech.
He also read another article on finance, in which Bentham and Mill were mentioned and subtle attacks were made on the Ministry.
I have tried to be patient with the subtle attacks on the moral values of my faith; this is the last straw.
One of the players of the season, he mixes subtle attacking skills with ferocious defence, and his exclusion from this week's Super League Dream Team robbed that hypothetical selection of much credibility.
What is strange to her, she said, are the subtle attacks against her and her 3-year-old son, who also carries the exalted name of his great-grandfather, Lázaro Cárdenas, a former Mexican president.
