Russia struggled to push the Ukrainians into the river after its planes were shot down, intel says, showing how a surprising failure at the war's start is still a problem

• Russia had relied on air support to attack Ukrainian advances in a southern sector of the front.
• But Kyiv recently shot down several fighter jets, putting that strategy in jeopardy.  
• It all comes back to key failures Russia made at the start of the war, Western intelligence says.

Russia has been unable to effectively drive Ukrainian forces from a key battlefield sector after the recent loss of several aircraft in combat. It shows how a surprising failure at the start of the full-scale war continues to haunt Moscow, according to Western intelligence.

Ukrainian forces in the fall established a bridgehead, or a strong foothold, on the eastern bank of the Dnipro River near the southern city of Kherson. The river had long been a critical natural barrier preventing advances, but Kyiv made a bold strategic move that is reigniting this area of the front.

To drive the Ukrainians back, Russia turned to its available airpower to attack the Ukrainian bridgehead, but that changed on Dec. 22, when Lt. Gen. Mykola Oleschuk, the commander of Ukraine's air force, said his troops shot down three Russian Su-34 fighter-bombers over southern Ukraine.

After the losses, the Russian air force almost completely stopped its crewed combat operations in the southern area through the end of the month, Britain's defense ministry said in a Saturday intelligence update.

The update added that there is a "realistic possibility" the the lack of support from the air "contributed to the failure" of Moscow's ground troops to clear the Ukrainian bridgehead.

More recently, "Russia has again increased tactical air strikes around the bridgehead, but at a lower level than before the shootdowns," the intelligence update read.

"This once again demonstrates that Russia's inability to establish air superiority in the early stages" of the invasion "continues to undermine their daily operations," it added.

One of many mistakes the Russian military made when it launched the full-scale invasion of Ukraine in February 2022 was that it failed to lead the assault with a substantial air campaign.

The Russian military was expected to clear the way for its ground assault with airpower that would destroy the Ukrainian air defenses and secure air superiority, but the Russian air force was largely missing in action, surprising many observers.

That unforced failure to commit its air forces to the fight at the start has been seen as a major blunder, one that helped give the Ukrainians a fighting chance. Russia never got the same opportunity again, and it has paid heavily for that mistake with lost fighters and helicopters in the time since.

Moscow has demonstrated that it can outmatch Kyiv in the skies thanks to disparities in force size, electronic and technical capabilities, and missile and radar performance, but neither Russia nor Ukraine has managed to establish air superiority because the formidable surface-to-air missile system capabilities on both sides. The airspace above the battlefield in Ukraine has remained contested.

Ukraine is hoping that its fortunes will change with the expected eventual arrival of US-made F-16 fighter jets, a handful of which have been pledged to Kyiv by some of its European backers. But when, exactly, these advanced aircraft are slated to arrive is unclear and could still be months away, if not longer.

Regardless of when they arrive, questions remain over how much of an impact the F-16s will actually have in the war. Aviation experts and former US military pilots previously told Business Insider that the fighter jets can be used in a variety of roles — both offensively and defensively — like fending off Russian missile attacks or striking ground assets — but might be vulnerable to the Russian military's more advanced air defenses.