Ukrainian forces have received military aid from 27 nations, some of it before the February 24 Russian invasion. In some cases, Ukraine had purchased additional numbers of some particularly useful items, like the Starlink terminals that can receive high-speed and encrypted Internet access via thousands of SpaceX Starlink satellites in service.
The most important donations have been the thousands of anti-tank and anti-aircraft weapons delivered since the invasion began. These are usually the latest models and some had little or no combat experience. That was quickly remedied as Ukrainian forces used these weapons to defeat the seemingly superior Russian forces.
The Ukrainian have provided donor nations with data on the performance of their donated weapons, many of which had never been used so extensively against a modern force equipped with modern armored vehicles, jet fighters and helicopters. Donors were also told how easy it was for Ukrainian troops and civilian Territorial Defense personnel to learn to use the new weapons effectively. This enabled some donors to modify the usability of their weapons, especially the ant-armor and anti-aircraft systems.
Since the first Russian attack in 2014, the Ukrainians had been preparing for a possible full-scale Russian invasion. Thousands of civilians had joined Territorial Defense units before the invasion. Ukraine knew there would be a lot more volunteers if the Russians did attack and prepared for that by having enough uniforms and weapons available as well as brief but intense training courses developed to handle the influx. Ukraine expected some additional foreign aid and had already received or purchased weapons and equipment from NATO nations before 2022.
The Ukrainians had developed tactics for the Territorial Defense Units that emphasized using small groups of armed personnel to attack Russian support units, especially supply vehicles. That was quickly modified when the unexpected flood of aid came in, including thousands of portable anti-tank and anti-aircraft weapons. Many Territorial Defense units were soon armed with these weapons so they could take on Russian tanks and other armored vehicles. This proved to be decisive in rapidly defeating Russian efforts to advance into Ukraine and capture major cities, especially the capital Kyiv.
Copies of the Russian war plan, as well as dozens of working Russian combat vehicles and hundreds of Russian troops were captured. The Russian plan expected the fighting to be over in 15 days with Kyiv captured and a pro-Russian government installed. The reality was that by day fifteen of the invasion about half of the Russian combat units; Battalion size task forces called BTGs or Battalion Task Groups, were destroyed or disabled by heavy losses. By the end of March many BTGs were withdrawn to Russia for rebuilding, a process that could take months. The rebuilding process quickly ran into problems when many of the armored vehicles held in reserve proved to be inoperable because of inadequate maintenance and security. Many of the replacement troops were conscripts, who serve only for a year and by law cannot be sent into a combat zone. Most of the BTGs used for the initial attacks had few or no conscripts and used volunteer troops who are paid more and have more military experience. Many of these contract (kontrackti) troops were now seeking to cancel their contracts and leave the military, which proved to be a riskier job than they were led to believe.
Many conscripts inside Ukraine simply surrendered at the first opportunity. Ukrainian troops and the government managed to let many Russian troops know that prisoners of war were well treated and families of the prisoners would be notified. The Russian government had imposed an information blackout on who their troops were in Ukraine and which of them were killed, wounded or captured.
Russia had few additional BTGs to replace those lost and by the end of March the Ukrainians were counter attacking and retaking Russian controlled towns and villages. The Russian supply lines were under attack day and night. The night attacks were effective because of the use of a small Ukrainian UAV equipped with GPS, a night vision camera, a laser range finder and a link to a nearby artillery unit via Starlink. The UAV patrolled Russian supply routes at night and, when a convoy was spotted trying the move safely in the dark, the artillery unit had the continually updated location of the trucks. That enabled the Ukrainians to fire at the convoy and destroy many of the vehicles while demoralizing the survivors who didn’t believe the Ukrainians could detect them in the dark and call-in accurate artillery fire.
The Russians never expected something like this and, once they figured out how this worked, had another reason negotiate peace. The Russians offered to leave but keep some of the Ukrainian territory they already occupied, like the Donbas (portions of two provinces in eastern Ukraine) and the Crimean Peninsula, both of which Russia seized in 2014. The Ukrainians demanded the Russians get out completely. In the meantime, Ukrainians keep attacking and inflicting casualties and equipment losses as well as starving Russian units in Ukraine of essential supplies.
The donor nations continue their aid shipments and are adding new items, like NATO AWACS (Aircraft Warning and Control) aircraft operating over Poland and Romania near the Ukrainian border to detect and track hundreds of aircraft in the air up to 400 kilometers away. This enables the AWACS to cover most of the primary combat zones and pass the information on to the Ukrainian forces. This is also done with photo satellite surveillance but the AWACS data is real-time while the satellite photos are hours or days old. Adjacent NATO countries also supply medical facilities for badly wounded Ukrainian troops as well as civilians and refuge for millions of Ukrainians who have fled the fighting. The aid is usually flown into Poland where Ukrainian trucks or railroad trains take it across the border to weapons distribution centers.
NATO also took the lead imposing unprecedented economic sanctions on Russia. These sanctions were immediately felt by all Russians. In short, the extent of the resistance to the Russian invasion was far greater than the Russians, and many Ukrainians expected. How soon this will end the war is still uncertain but the donor nations now know how well their weapons work against modern combat vehicles manned by well-trained troops. The world and Russia now know how overrated Russian armed forces are. This is a lesson for every country.