Will Russia Control the Skies over Ukraine?
Recently leaked classified documents from the U.S. Department of Defense (DOD) warn that Ukrainian air defense is nearly out of missiles. Clearly, this is bad for Ukraine, but how bad? Will the Russian air force roam the skies over Ukraine and change the course of the war? Fortunately, this is unlikely in the near term. Russian aircraft will remain vulnerable and unlikely to overfly Ukrainian territory. Cruise missiles and drones are a different matter. Ukraine will be able to defend its military forces with its remaining air defenses but not its cities or infrastructure. Ukraine’s electrical grid could be damaged beyond what was seen last winter, inflicting a new level of civilian suffering. Over time, as Ukrainian air defenses weaken, the situation will become increasingly dire if NATO does not provide more air defense assets.
What Leaked DOD Documents Said
As is now well known, 100 classified DOD documents appeared in open sources, allegedly leaked by a junior Air Force enlisted member. The documents themselves have been withdrawn from the internet and are unavailable for analysis. However, the New York Times, Washington Post, and others have reviewed and written about the documents.
One of the major revelations is that Ukrainian air defense may run out of missiles by May. The New York Times reported, “Stocks of missiles for Soviet-era S-300 and Buk air defense systems, which make up 89 percent of Ukraine’s protection against most fighter aircraft and some bombers, were projected to be fully depleted by May 3 and mid-April, according to one of the leaked documents.” This might allow Putin to “unleash his lethal fighter jets in ways that could change the course of the war.”
The State of Ukrainian Air Defense
Air defense has always been a Ukrainian weak point but became a crisis in the autumn when Russia began focusing attacks on infrastructure and causing hardship to the Ukrainian population. CSIS analysis noted that the United States, NATO, and other countries had relatively little air defense capability to provide because most of their ground-based air defense had been deactivated after the Cold War.
The two tables show the current state of Ukrainian air defense systems. Ukrainian inventories are from the International Institute for Strategic Studies The Military Balance 2023, and Ukrainian losses are from the Oryx online database, Attack On Europe: Documenting Ukrainian Equipment Losses During The 2022 Russian Invasion Of Ukraine, probably the best source on both Russian and Ukrainian losses because they require photographic evidence, though that does mean they probably undercount losses. Contributions to Ukraine from NATO and other countries come from the Stockholm International Peace Research Institute’s Arms Transfers Database. Some numbers were adjusted based on data contained in classified Joint Staff documents that were published by the New York Times.
The first impression from both tables is that there is not much green, and that, unfortunately, is an accurate impression. Ukrainian air defenses are limited and declining. An ironic situation emerging from Table 1 is that the Ukrainians still have a relatively large number of Soviet-era air defense launchers but a dwindling number of missiles. For example, the country has over 100 medium-range surface-to-air missile (SAM) launchers, specifically the S-300/SA-10 and Buk-M1/SA-11. These have been the backbone of Ukrainian air defense, and their missiles have been fired in large numbers to defend against attacking Russian cruise missiles and drones. These defenses have reportedly been effective, shooting down about 80 percent of Russian attacking missiles. However, with a limited number of missiles remaining, Ukrainians will need to hold them for the highest-priority targets—Russian aircraft or missiles heading for the most sensitive targets.
Before the war, Ukraine had only a small number of short-range SAMs, and these are likely exhausted. Ukraine also had a small number of ground-based gun systems, which, although obsolescent, may have some continuing capability against slow-moving drones.
The situation with fighters is better. Although the numbers are limited, probably under 50, NATO has provided spare parts to keep them operational. Ukrainian fighters operating over home territory can provide some defense against Russian fighters and missiles.
Table 2 shows systems provided to Ukraine since the war began. There are large numbers of short-range systems, including the U.S. Stinger and Avenger, the Polish Piorun, the French Crotale and Mistral, and the German IRIS-T. Standard practice is to distribute these systems among the frontline troops to protect them from air attack. The Joint Staff documents indicate that they are deployed this way. A few may be stationed at critical infrastructure locations such as power plants.
A key question here is how many Stingers remain. About 2,500 were sent to Ukraine, but the Joint Staff documents indicate that only about 190 remain. That is a big change. The small numbers indicate a lot of gaps in the Ukrainian frontline air defense. The large numbers of Polish Piorun and German Strela short-range missiles might fill some of these gaps.
NATO has sent small numbers of medium-range systems, such as the U.S. Patriot, the Italian/French Aster/SAMP/T, the NATO Hawk, and the Norwegian/U.S. National Advanced Surface-To-Air Missile System (NASAMS). These are excellent for defending cities and critical infrastructure. The problem is that the HAWK and Aster/SAMP/T are only available in small numbers. Systems with large numbers of available missiles, such as NASAMS, have only a few launchers (two). Ukraine is receiving four Patriot batteries, and the missiles are in production, thus providing good coverage of four cities. However, there are limits: the missiles are expensive ($4 million each) and unsuitable for defending against inexpensive drones.
Ukraine retains enough air defense systems that it would still be very dangerous for Russian aircraft to overfly the front lines and key military facilities. The number of Russian aircraft is small enough that even with reduced missile inventories, the Ukrainians could shoot at all of them.
This is not the case with drones or kamikaze missiles. Because resupply is limited or impossible, Ukraine cannot fire too many air defense missiles at Russian cruise missiles and drones, of which there are hundreds. The leaked Joint Staff documents make this point by saying that “only selected [Ukrainian] assets can be covered,” and the air defense system can “only engage [Russian] TACAIR.”
Continuing Russian Missile Attacks
Since the beginning of the conflict, analysts have expected Russian missile attacks to ease off as Russia fires more missiles than its industry can produce. Indeed, the intensity of missile attacks did taper off from the high levels of the summer. However, a recent CSIS study shows that attacks have been relatively constant over the last few months.
The critical element to watch is Iranian and Chinese support. Iran has already sent hundreds of “kamikaze drones,” such as the Shahed-136. Sending more will strain Ukrainian air defense. The Chinese have sent components but not complete systems. If China changes its policy and supplies weapons and munitions, that will improve Russian capabilities for air attack.
Fears are unfounded that Russian aircraft will roam the skies over Ukraine and freely attack targets. Ukraine has enough remaining air defense capability to make its airspace extremely dangerous to Russian aircraft. Further, the Russian air force has shown itself to be risk averse because of deficient training and inadequate defensive systems. Russian aircraft rarely enter Ukrainian airspace but launch weapons from Russian territory. Thus, the Joint Staff statement that “[Ukraine risks] losing the ability to mass ground forces on the [front line] and counteroffensive” is excessive. For the next few months at least, the Russians will be unable to use declining Ukrainian missile inventories to gain a major battlefield advantage. The long-expected Ukrainian offensive will be able to go forward.
It is the ordinary Ukrainian citizen who will feel the effect. Until now, Ukrainian air defenses have been able to reduce, though not prevent, damage to infrastructure, particularly the electrical grid. As the Ukrainian inventory of defensive missiles declines, more Russian cruise missiles and drones will get through, causing more damage, more electrical outages, and more civilian suffering. From a cold-blooded military perspective, this is acceptable because military operations will be able to continue with less interference, but it is little comfort to a suffering population.
Despite the militarily tolerable near-term prospects, there is a long-term crisis building as Ukrainian air defense assets get used up. As defenses weaken, the Russians will get bolder and more aggressive. To prevent Russia from gaining a significant operational advantage, Ukraine needs some enhancement or resupply of its air defenses. Although a few Soviet-era systems may still be available on the world market, they are scarce. Only NATO systems can fill the void. For NATO countries, this means accepting a higher degree of risk by taking systems from their own forces and reducing munitions inventories below desired levels. However, it is better to win the war at hand rather than lose it in favor of a future war that may never occur.
Mark F. Cancian is a senior fellow in the International Security Program at the Center for Strategic and International Studies in Washington, D.C.