The phrase "a determined enemy" is correct and usable in written English.
It can be used to describe an adversary who is resolute and persistent in their actions or intentions.
Example: "In the face of a determined enemy, the soldiers prepared themselves for a long and challenging battle."
Alternatives: "a resolute foe" or "an unyielding opponent".
Mr. Johndroe continued, "This is going to be a long battle against a determined enemy, and I can assure you that the president and his national security advisers focus on this every day and will continue to do what is necessary to protect the American people".
The administration has apparently determined the safest thing to do politically is to chart a course toward withdrawal and otherwise pretend the United States does not still have tens of thousands of soldiers and marines fighting a determined enemy on a daily basis.
How did a determined enemy that had executed so devastating a strike fail so completely to repeat its lethal success?
"We have a determined enemy and you can't put the United States in a big Tupperware container.
Though Companycommand and Platoonleader require passwords, they could presumably be hacked, and a determined enemy could learn a good deal about how officers think.
AYN RAND The author learns philately The author of "Atlas Shrugged" — and a determined enemy of "collectivism" — took up stamp collecting in her mid-60s.
The American-endorsed plan to challenge Khan's leadership and strengthen Karzai's national standing inside Afghanistan, it seemed, had served to make Khan a more determined enemy.
What some members of Congress have called the greatest failure in American intelligence since Pearl Harbor was also a failure to recognize an open and determined enemy.
But even the Pentagon acknowledges that Taliban and Al Qaeda affiliates "still operate with impunity from sanctuaries in Pakistan" and that "the insurgency remains a resilient and determined enemy".
All of us in the military knew, and made clear, that this would be a long, hard summer for our people in Afghanistan; that they faced a resilient and determined enemy who would make every effort to disrupt our work to support the development of effective governance in Helmand province.
Although out-balanced in strength and numbers by a desperate and determined enemy, Rear Admiral Callaghan, with ingenious tactical skill and superb coordination of the units under his command, led his forces into battle against tremendous odds, thereby contributing decisively to the rout of a powerful invasion fleet and to the consequent frustration of a formidable Japanese offensive.
