Ukrainian President Volodymyr Zelenskyy will soon be crossing another hot ticket item off his weapons wishlist.
After months of refusal, the US has made a sharp reversal on its stance to allow the supply of advanced Western fighter jets to Kyiv.
At the Group of Seven (G7) summit in Japan over the weekend, President Joe Biden endorsed training programs for the sophisticated F-16s and said he would not stand in the way of allies transferring the US-made jets to Ukraine.
Several NATO countries had voiced support for sending their supplies of F-16s into the conflict, but it required US government permission.
Details on how many of the fourth-generation jets would be sent, and who would provide them, will be made in the coming months while training is underway, Mr Biden said.
The use of air power has been largely untapped throughout the conflict, with both sides struggling to gain superiority over the skies.
The destructive power and global availability of the F-16s is expected to help break the land warfare slog and shift the balance Ukraine's way.
But, given their complexity, defence experts say that is unlikely to happen anytime soon.
"It's a game changer in many respects," retired Air Marshal, Geoff Brown, told the ABC.
"But it's just not that easy to implement."
John Conway, managing director of consultants Felix Defence, said a whole "system of systems" needed to be built to get crews combat-ready and the jets off the ground.
"It's the broader apparatus of the Western air power system that would need to be put in place, including sustainment, pilot and ground crew training, and operations support functions," said Mr Conway, a retired Royal Air Force group captain.
"You can't just throw a bunch of F-16s in there and expect them to work overnight."
While there may be ways to shave off time to get Mr Zelenskyy's desired "wings for freedom" in the skies, the move is widely seen as a long-term strategy.
So what exactly is at play, and what will it take to get Ukraine set for Western jets?
The F-16 advantage
Along with F-16s, Eurofighter Typhoons and Sweden's Gripens were on the top of the list.
While Gripens are tactically well-suited to the environment, there aren't so many available.
Mr Conway said when it came to Ukraine's long-term objectives, the F-16 made the most sense.
The F-16 is one of the world's most prolific and versatile multi-role fighter aircraft.
It is currently operating in 25 countries, according to maker Lockheed Martin.
The F-16 has both air defence and ground attack capabilities — and can conduct them at the same time.
Its advanced radar system also allows it to detect targets up to around 370 kilometres away.
"It's a pretty good air-to-air fighter against other airplanes, it's also got a good air to ground weapon system," Mr Brown said.
"They can be loaded with bombs and air missiles so it can do both things at the same time.
"All in all it's a pretty good all-round airplane."
What does Russia have up its sleeve?
Peter Layton, visiting fellow at the Griffith Asia Institute, said Russia had mainly been using modernised versions of late-Cold War Soviet aircraft.
"The most effective use of Russian aircraft has been firing long-range air-to-air missiles, and firing long-range cruise missiles while flying safely in Russian air space," he said.
"There has been some use of 1980s Su-25s in low altitude ground attacks, but these missions have been ineffective and they have lost a lot of aircraft."
Russia also has the stealth SU-57 — its most advanced supersonic combat jet — up its sleeve.
But according to the UK's Ministry of Defence (MOD) Intelligence, they are unlikely to face-off against the F-16s.
In an assessment earlier in the year, the MOD said it expected Russia to continue playing it safe.
Moscow had been taking a "risk-averse approach to employing its air force in the war" over the potential loss of sensitive information and the reputational damage it may cause, the MOD statement said.
Which countries are stepping up support?
The US had been reluctant to allow Western jets to be sent to Ukraine due to worries that it could escalate tensions with Russia.
Mr Biden said he had received a "flat assurance" from the Ukrainian president that he would not use the American-made F-16s to go into Russian territory.
Jessica Genauer, senior lecturer in international relations at Flinders University, said the US decision followed a consistent pattern of incremental escalation of military assets the West has supplied to Ukraine.
Despite Russia's threats of retaliation, main battle tanks, long-range missile systems and now fighter jets have been approved.
"Importantly, the much-feared use of a tactical nuclear weapon by Russia, as a response to Western increases in supply of important military equipment, has not eventuated," Dr Genauer said.
Over the weekend, Russian Deputy Foreign Minister Alexander Grushko warned Western countries would run "colossal risks" if they supplied Ukraine with F-16s, TASS news agency reported.
Russia's ambassador to the US, Anatoly Antonov, wrote on the embassy's Telegram channel on Monday that the transfer of F-16 jets to Ukraine would also raise the question of NATO's role in the conflict.
Dr Genauer said the move was also a testament to Mr Zelenskyy who had been persistently rallying Western partners towards agreement on the supply of fighter jets.
His speech to UK parliament in February, in which he thanked Britain in advance for its powerful planes, seemed like "wishful thinking".
"Now — a little more than three months later — this wish has become a reality," Dr Genauer said.
Several European air forces have been replacing their F-16 fleets with newer aircraft, so supply shouldn't be an issue.
The Dutch alone have around 40 on hand.
On a tour of European capitals last week, Mr Zelenskyy received pledges from British Prime Minister Rishi Sunak and his Dutch counterpart Mark Rutte to help build a "jets coalition", although both leaders have stopped short of saying they will send planes.
Mr Sunak said his country would work with the Netherlands, Belgium and Denmark "to get Ukraine the combat air capability it needs".
There are also plenty of countries that can assist with training, maintenance and offering spare parts, Mr Brown said.
"There's a lot of skilled maintenance operators that you could actually draw on," he said.
"You can have pilots fly on aeroplanes, but at the heart of really good air forces is engineering and logistics.
"If you can't make the planes fly, they're not much use."
Cutting down training time
Training on F-16s will take place in Europe, US officials have said, estimating at least 18 months was needed for training and delivery.
London has already agreed to start training Ukrainian pilots in the northern hemisphere's spring, and said it will look at shortening the sessions for experienced Ukrainian pilots.
Dr Layton said normal peacetime training on a multi-role jet would take between five to six months.
But if they stick to air defence, it would be possible to teach Ukrainian pilots to fly an F-16 in three months.
"The Ukrainian fighter pilots are highly motivated, they are clearly good pilots and have a lot of experience flying fast jet aircraft," he said.
"And if they stick to air defence tasks, at least early on they can learn on the job."
Teaching pilots to carry out low-altitude, night and all-weather ground attacks using infrared systems and laser-guided bombs would take much longer, he added.
Mr Brown agreed that training may not take as long as people think.
"It just depends on how they do it," he said.
He said when the Australian Army started providing Ukrainians training on its Bushmaster armoured vehicles, the program went for three weeks.
It was soon shortened to three days and can now even be carried out within hours.
"The US has actually been training Ukrainians since before 2014," Mr Brown said.
"So the Ukrainians are pretty up to date with Western tactics, which is probably the biggest challenge."
'Decoupling' the big picture strategy
While cutting training time may be possible, the jets are still unlikely to have a significant impact in the short term or play a role Ukraine's planned counteroffensive.
Mr Conway believes the move is more part of the larger aim to move Ukraine away from its reliance on Russian technology and weapons.
"The big game is the decoupling from the Russian combat system and the Russian industry supply chains," he said.
By integrating into the Western air combat system, Ukraine will gain access to the advanced technologies it needs to "survive against Russian threats".
But there are many moving parts, including setting up infrastructure, ground control and intelligence systems that integrate with the fighter jets platform.
Then there are the broader issues of creating the cultural and conceptual changes allied with NATO, Mr Conway said.
"That is a huge task, which is 10-times more challenging than acquiring a new fleet of aircraft," he said.
"This is a real big picture strategic play that's going to take years and years and years to play out."
German Chancellor Olaf Scholz said the potential allied training programs for Ukrainian pilots on F-16s sends more of a message at this stage.
"The training of the pilots is a longer project," Mr Scholz told reporters before leaving the G7 summit over the weekend.
"The US has not finally decided what stands at the end.
"The project has a message for Russia: Russia cannot count on winning if it bets on a long war."
ABC/wires
