The lack of systems needed in the event of war exposes vulnerabilities according to the alliance's assessments, writes the Financial Times.
Europe has only a fraction of the air defence capabilities needed to protect its eastern flank, according to internal NATO calculations, revealing the extent of the continent's vulnerability.
Russia's war against Ukraine has highlighted the importance of air defence as Kyiv asks the West for additional systems and missiles to protect its cities, troops and energy grid from daily bombardment.
But according to people familiar with confidential defence plans drawn up last year, NATO states can provide less than 5% of the air defence capacity deemed necessary to protect its members in central and eastern Europe from a full-scale attack.
One senior NATO diplomat said the capability to defend against missiles and airstrikes was "a core part of the plan to defend Eastern Europe from invasion. We don't have that at the moment."
NATO foreign ministers will gather in Prague today, May 30, for two days of talks aimed at preparing the alliance's leaders' summit in Washington in July, where strengthening European defence will be a key topic.
Some European leaders and military officials have said that by the end of the decade, Russia may be able to attack a NATO member state.
In a major defence review last year, the UK government described "the challenge of defending against an attack from the sky" as "the most serious for over 30 years".
Russia's use of Soviet-era missiles, drones and highly destructive "floating bombs" in Ukraine has added urgency to NATO members' efforts to boost defence spending after decades of military budget cuts.
"Air defence is one of the biggest holes we have. We can't deny that," said a second NATO diplomat.
The failure of European NATO nations in recent months to provide additional air defence equipment to Ukraine has highlighted the continent's limited supply of the expensive and slow-to-produce systems.
It has also spawned a series of overlapping initiatives trying to find long-term solutions. Last year, Germany launched its Sky Shield initiative with more than a dozen other EU countries to develop a common air defense system using technologies developed by the US and Israel.
However, France publicly criticized this proposal and proposed a competing concept supported by a smaller number of allies.
Last week, Poland and Greece called on the European Commission to help develop and possibly help finance a pan-European air defense system, a proposal Commission President Ursula von der Leyen has indicated she will support.
Some EU capitals have proposed increasing total debt to finance defense projects.
In a letter sent to von der Leyen, the prime ministers of Greece and Poland, Kyriakos Mitsotakis and Donald Tusk, described air defense as "a major vulnerability in our security", adding that the war in Ukraine "has taught us lessons that we cannot more to ignore".
The proliferation of low-cost, long-range drones such as those used by Russia against Ukraine has heightened these concerns.
"Long-range strikes are no longer a superpower capability," said one Western defense official.
A NATO official said "capability targets and defense plans are classified," but added that air and missile defense "are top priorities" and that "stockpiles have been reduced."
"NATO's new defense plans also significantly increase air and missile defense requirements in terms of quantity and readiness," the official said, adding that the countries are investing in new air defense capabilities, including fighter jets.
Immediately after Russia's full-scale invasion of Ukraine in February 2022, the US deployed a Patriot air defense system to protect an airport in southern Poland that has become a hub for supplying Western arms to Kiev.
But officials say NATO members have so few such systems that their capacity to deploy more outside their own territories is severely limited.
In the United Kingdom, the Royal Navy's six Type 45 destroyers are equipped with anti-missile defense systems, but the vessels face design flaws.
The British Army also has six modern Sky Saber ground-based air defense systems, but their interceptor missiles only have a range of about 40km and two of the systems are overseas.
"The UK's air defense capabilities are completely inadequate," said Jack Watling, senior research fellow at the Royal United Services Institute think tank in London.
Full integration of Europe's various air defense systems could help make up for the shortfall by creating a dense network of sensors and interceptors across the continent.
But "attempts to renew NATO's air defense command and control infrastructure never got off the ground," Watling said. /BGNES
