Analysts said the missiles forced Russia to adjust its air operations, but did not stop it. On Monday, a senior US defense official said Russia had carried out about 300 sorties in the past 24 hours, up from an average of about 200 the day before the war.

“It’s very likely that the Russian Aerospace Forces have modified the way they conduct operations,” said Michael Kaufman, director of Russian studies at CNA, a Virginia-based think tank. “There is either an attrition in a large percentage of the Ukrainian air defenses, or they are more careful about how these sorties are carried out.”

Analysts said the increase in Russian flights could likely be attributed to several factors.

While there are information gaps, Kaufman said, Ukraine appears to have concentrated its high-powered air defenses in a few locations, including the capital, Kyiv, and the second-largest city, Kharkiv. This has given Russia greater freedom to carry out an increasing number of air strikes around the southern port city of Mariupol, where Fierce urban fight Russia continues to set its sights on what will be its first strategic victory in the war.

“You haven’t seen a lot of Russian planes shot down around Mariupol, but you can see that they did a lot of strikes,” Kaufman said. “You feel that the Ukrainian army decided to defend certain regions over others.”

The vast quantities of MANPADS that Ukraine now possesses have created challenges for Russia in low-flying helicopters and jets, but they appear to have been modified by staying out of range too often.

A senior defense official, who spoke on the condition of anonymity under ground rules set by the Pentagon, said a “significant number” of Russian flights in the war do not leave Russian or Belarusian airspace. Russia has launched airstrikes on Ukraine several times from outside Ukrainian airspace, including cruise missiles from long-range bombers. At a military training center in Yavoriv, ​​western UkraineUS defense officials said. Other Russian planes are venturing into Ukrainian airspace only for short periods.

The Pentagon continued to say that the airspace over Ukraine is in dispute, surprising analysts who had predicted that Russia would quickly control the skies.

Some lawmakers question the Pentagon’s assessment. In a letter he sent to President Biden earlier this monththey wrote that Russia had already demonstrated air superiority, and said that if Ukraine did not receive additional military assistance, Russia’s advantage “could soon develop into air dominance.”

Rob Lee, a former Marine Corps officer who is now a senior fellow at the Foreign Policy Research Institute, said it appears that Russia mostly operates Su-25 aircraft and helicopters over southern Ukraine. They operate the more advanced Su-35 from Belarus, he told me, and are likely to shoot down Ukrainian UAVs and planes.

The Su-25, nicknamed Frogfoot, operates somewhat like the American A-10, attacking ground targets while flying at a relatively low altitude on the ground. Kaufman said both Ukraine and Russia lost their Su-25s in the war, in part because they had “outdated” technology that made them vulnerable.

Kaufman said other weapon systems that were largely missing initially from the war have appeared on a larger scale, including the Russian Orlan-10 drone. With a wingspan of about 10 feet, it is used by Russian forces to provide aerial reconnaissance of potential ground targets. Several images of the drone, which have not been independently verified, have been circulating on social media in recent days after some of them were apparently shot down.

“I really started to see some capabilities that were very missing from the opening of the Russian campaign,” Kaufman said.

Since unverified images from the battlefield show that Russia has started using “idling munitions” over Ukraine, the Pentagon is expected to deliver Ukraine its own idling munitions soon in the form of Switchblade Drones.

The single-use weapons are cheaper than most US drones and come in two sizes, according to AeroVironment, the manufacturer. The Switchblade 300 weighs about five pounds and is designed to be carried in a backpack to assist small infantry units. The Switchblade 600 weighs about 50 pounds and can target armored vehicles. It was not clear what copy the United States would send to Ukraine.

While the United States and its allies have sought other ways to bolster Ukraine’s air defenses, they have also imposed restrictions. Including Rejection of a proposal from Poland The MiG-29s were to be transported to a US base in Germany and then sent to Ukraine.

US officials said the planes would have been of limited value, considering that Ukraine moves its current planes only a few hours a day due to Russian surface-to-air missiles. Officials said the transfer could also provoke an attack on NATO countries by Russian President Vladimir Putin.

David A. Deptula, a retired Air Force general, said it was time to reconsider that decision, in light of Putin’s continued attacks on civilian targets.

“Everything is fair in providing weapons to Ukraine even direct US/NATO involvement against the Russians in the fighting,” Deptola, now dean of the Mitchell Institute for Space Studies, said in an email. “Ukrainians are fighting on behalf of the whole free world, and therefore we must support them to the fullest extent possible, not least what we can handle according to White House and Pentagon lawyers.”

Ukrainian President Volodymyr Zelensky has also sought more powerful air defense systems that Ukrainian forces already know how to use, such as the S-300, but there is no indication that the Biden administration was able to broker a deal to send any.