Is after the battle tank before the fighter jet? After promising to supply main battle tanks from countries like the US and Germany, Ukraine has renewed its demand to also be equipped with Western-style fighter jets – and some allies are at least receptive to a discussion about it.

Shortly after the beginning of the Russian war of aggression, the delivery of fighter jets was categorically ruled out. In March of last year, the US government opposed such a move by Poland and warned of a “significant Russian reaction”, as Pentagon spokesman John Kirby said at the time. The topic was off the table for the time being.

Now they want to “discuss the matter carefully,” Jon Finer, US President Joe Biden’s deputy national security adviser, told MSNBC on Thursday. “We have not ruled out or promised any particular systems in advance.” Support will be tailored to what Ukraine needs.

France also wants to “leave all doors open”, as the chairman of the defense committee, Thomas Gassilloud, was quoted as saying by the “Guardian”. Dutch Foreign Minister Wopke Hoekstra said last week that there were “no taboos” on military support. His country is “open” to any inquiries. In Poland they would be ready for a delivery of combat aircraft in the NATO collective.

However, the cautious statements do not mean that the supporter countries are actually considering the delivery of combat aircraft to Ukraine – but neither does an explicit rejection. There could be several considerations behind this.

In the course of the war, the red lines in military aid have shifted several times – and could do so again. Washington has signaled to Kyiv that the delivery of planes is “a no-go for now,” Politico quoted a diplomat from northern Europe as saying, adding, “There’s a red line – but last summer we had a red line on the Himars (multiple rocket launchers) and that was moving. Then it was main battle tanks and that was moving.”

Last but not least, Kyiv hopes that there will at least be some movement in the debate. “The next big hurdle will be fighter jets,” Yuriy Sak, an adviser to Ukraine’s defense minister, told Reuters. “If we can get them (modern western fighter jets) it will mean immense advantage on the battlefield.”

That’s a belief shared by military strategists like Justin Bronk. However, the researcher at the RUSI think tank in London warns on Twitter that Western combat aircraft are also at high risk from Russian surface-to-air missiles and require logistics, personnel and training. “The question is, should this be a priority now or should it wait?”

The gradual increase in Ukraine’s combat capability – or the reassessment of red lines – follows a strategy described by the “Frankfurter Allgemeine Zeitung” as “boiling the frog”.

The article outlines Joe Biden’s approach – which probably also follows Chancellor Olaf Scholz (SPD) -, firstly not to supply any weapons with which Ukraine could attack Russia, and secondly to gradually arm the Ukrainian army better so that the Russian President Putin always has to ask whether he considers the threat posed by the increased Ukrainian clout to be so great that he would seek direct confrontation with the West and expand the war.

“American officials once called this process ‘boiling the frog’ – based on the story of a frog that jumps out of the pot as soon as you put it in boiling water, but not if the water is heated slowly.”

The delivery of main battle tanks has raised the temperature, as the first reactions from Moscow show. The delivery of fighter jets would do the same if they represented a new quality of weapon aid. And it is to be expected that such a debate would be even more heated than the tough tug-of-war over the tank pact.

Germany has already ruled out such deliveries. “I made it clear very early on that it’s not about combat aircraft and I’m doing the same here,” said Chancellor Scholz on Wednesday in the Bundestag. He and US President Biden made that clear in the discussion about no-fly zones over Ukraine that arose at the beginning of the war. “We will not do that,” he said at the time. “Nothing has changed in this attitude and nothing will change.”

It remains to be seen whether a consensus could be reached to also equip Ukraine with western combat aircraft. The apparently desired fourth-generation jets, such as the USA’s F-16, might not be an option at first because of the organizational hurdles. Instead, however, Ukraine could receive Soviet-designed aircraft, similar to the early tank deliveries. Shortly after the beginning of the war, Poland failed with that attempt to deliver MiG-26 jets.

The fact that some Western supporter countries are at least letting the public debate on the deliveries of fighter jets continue – although the tank decision was only made – could therefore have another reason.

On the one hand, the delivery of the battle tanks should enable Ukraine to defend itself against the Russian invaders, on the other hand, the western allies want to send a signal to Moscow that military support for the country will not run dry – and that they will stand by Kyiv as long as it does is necessary.

“The message, carefully weighed, carefully balanced with what we’ve been doing for the last few months and are doing again now, is that Putin (the Russian President) cannot count on support for the Ukraine is slowing down,” said Federal Chancellor Scholz in the ZDF interview with a view to the delivery of the Leopard main battle tank.

US President Biden made a similar statement when he announced the sale of the Abrams main battle tank. “The tanks are not an offensive threat to Russia, there is no threat of an offensive on Russian territory. If Russian troops retreat to Russia, where they belong, then this war would be over today.”

In other words, military aid to Ukraine is not being slacked off – if that gets too hot for Putin, he can withdraw Russian troops at any time. The fact that the mere option of fighter jets for Ukraine is not publicly dismissed by some supporter countries could therefore be calculated – the warmonger from the Kremlin should follow the statements carefully.

Sources: “Politico”, Reuters, CNN, “Financial Times”, n-tv, Bundestag (plenary minutes), Deutschlandfunk, editorial network Germany, “Spiegel”, MSNBC, “Guardian”, “NL Times”, “Tagesspiegel”