Ukrainian officials have long pressed their Western military backers to send them modern fighter jets, arguing Kyiv needs the airpower boost to best the invading Russian forces, and while some in the West agree, others argue fighter aircraft like the ones Ukraine wants wouldn’t stand a chance in the current threat environment.

There have been repeated requests for the delivery of American-made F-16s, leading to debates over how effective the fourth-generation plane would be in the skies. One former F-16 pilot told Insider he wouldn’t want to attempt to fly missions over Ukraine right now, asserting that the aircraft can’t outmatch Russia’s air defense systems.

Fourth-generation fighters “have no business in a modern-day battlefield,” John Venable, a 25-year veteran of the US Air Force, told Insider in a recent interview.