The Pentagon says Ukraine’s airspace remains contested several months into the Russo-Ukrainian War, raising questions about the Russian military’s effectiveness and combat power. A simple look at global firepower reveals that the Russians operate more than 770 fighter jets, compared to Ukraine’s sixty-nine or so. That's a glaring, massive deficit.

So why aren't the Russians able to achieve air superiority?

Pentagon spokesman John Kirby has one answer: Ukrainian air defenses. “...[O]ne of the reasons [Ukraine’s airspace is] contested is because Ukrainians still have a viable air force of their own and they also have a very effective air defense capability both short and long-range air defense capability. And we know that it's having an impact on Russia because not only do they not have air superiority but because of the kinds of flight profiles that they're flying. Most of their sorties never even leave Russian air space,” Kirby told reporters on May 10.

Ukraine reportedly operates SA-15 Gauntlet Soviet-era air defense systems as well as Russian-built S-300s. The Pentagon says these air defenses are being used in a very tactically adept and effective way. Modern air defenses these days have digital processors, better networking, and longer ranges, and they can connect with other systems across a wider defensive envelope. They also can detect a wider sphere of frequencies, making them more effective.

This might explain more of Ukraine’s success: the Russian Air Force is mostly a fourth-generation air fleet, comprised of Su-30, Su-35, and MIG fighters. However sophisticated these aircraft are, they are unstealthy, leaving them vulnerable to anti-aircraft fire.

One of the things that spring to mind is Russia's fleet of Su-57s, the fifth-generation stealth fighter jets intended to rival the F-35. Are they being used? Well, according to TASS, Russia’s news agency, only a handful of them exist and there is a current contract to acquire as many as seventy in coming years, while the U.S. Air Force already operates roughly 300 F-35s. And as the war in Ukraine has revealed, Russia’s inability to operate uncontested highlights how stealthy has become a necessity for modern warfare. Simply put, fourth-generation aircraft are too easy to detect and take out. With something like a Su-57, surveillance Radar may be able to detect that something is flying, but may lack the technical capacity to engage it, meaning that the system can neither target, track, nor take out that aircraft. That's the advantage of something like an F-35 or an F-22: targeting a stealth aircraft requires a much more narrow and specifically-configured radar beam. Simply put, the Russian Air Force’s lack of aerial stealth capabilities could be a major region why Russia cannot dominate its neighbor’s skies, despite its numerical superiority.

Kris Osborn is the defense editor for the National Interest. Osborn previously served at the Pentagon as a Highly Qualified Expert with the Office of the Assistant Secretary of the Army—Acquisition, Logistics & Technology. Osborn has also worked as an anchor and on-air military specialist at national TV networks. He has appeared as a guest military expert on Fox News, MSNBC, The Military Channel, and The History Channel. He also has a Master's Degree in Comparative Literature from Columbia University.

Image: Reuters.