The heads of the British and French air forces warned Friday that Western dominance in the skies is increasingly under threat as rival powers develop new defence capabilities.
Head of the Royal Air Force, Stephen Hillier, referred to the development of new sophisticated surface-to-air missiles and fifth-generation fighter jets by Russia that challenge Western technological superiority.
"The global situation has changed, and fast, and we need to wake up to the fact that the control of air space too is being contested to a degree we have not witnessed in the post Cold War years," he said in Paris.
As well as Russia, China is investing heavily in new stealth fighter jet technology as part of a vast overhaul of its armed forces.
French air force chief Andre Lanata pointed to the loss of an Israeli F16 fighter jet over Syria in February, which was hit by Syrian anti-aircraft fire, as an illustration of the dangers.
"Our adversaries, our rivals have understood the advantage we have from our aerial power... today they are developing increasingly robust strategies to keep us out of the air," he said.
He urged policymakers to "really understand that control of air space in the future will be contested to an unprecedented degree.
"It's a major issue for our defence," he added.
Hillier was in Paris for a ceremony to mark the 100th anniversary of the RAF which was officially formed at the end of the First World War.
He was also highly critical of Russia.
"It is now clear that the threat posed to our societies and their national interests by state actors and their proxies has grown to proportions we have not seen since the fall of the Soviet Union," he said.
"Russia provides the most telling and pressing example."