Can Europe defend itself ‘without’ the US?

The prospect of a second Donald Trump presidency and, in particular, his recent pick of JD Vance as vice-presidential candidate have further increased the sense of alarm within the “transatlantic community.” The balance of US commitments to NATO’s main mission, the defence of Europe, is already under heavy pressure due to the Chinese pressure on Taiwan. As previously explained in these pages, American military resources will be increasingly drawn away from the North Atlantic to the Indo-Pacific regardless of who runs the White House.

This may be a secular trend but nuance matters. Both the Democrats and the establishment Republicans, on the whole, remain strongly committed to NATO. They might redeploy significant US forces to Asia (like Barack Obama intended after 2012) and they might insist that the Europeans take up more of the burden – but they would not put Article 5 in doubt. 

In turn, that logic effectively guarantees that the key elements of US military contribution to NATO, particularly in terms of the essential nuclear dimension and practical command and control capabilities (as well as actual planning assumptions), would stay in place. If war came, the “wiring” and the political will would be there to make a surge of US forces to Europe at least viable.

But under a Trump-Vance administration, America’s role in NATO might well come up for a fundamental review, including Article 5 commitments. The fact that this did not happen last time, and that in fact the “Trump scare” served to make the Alliance stronger, doesn’t mean it won’t happen now. The situation is very different, both in geostrategic terms and in terms of domestic US politics. Trump’s MAGA base, which Vance represents, is strongly for retrenchment in international affairs. 

Importantly, this is not “isolationism”: even among America First hardliners no one actually argues for closing all US bases worldwide and pulling up the drawbridge. But the dominant school of thought in Trump-world is that the US must focus overwhelmingly on China as the most important strategic threat to the US national interest (which, in itself, is probably true), while Europe must be able to defend itself and not rely on America as it has done since 1945. 

But what does that actually mean? The thought of trying to deter or indeed fight Russia without US military power in the frontline mix (at least not from the start) is frightening to Europeans, and for good practical reasons. It is also paralysing morally: no one really wants to have this hard conversation, for fear of appearing disloyal to the sacrosanct transatlantic spirit. 

To even conceive of fighting without the Americans feels akin to the medieval crime of “imagining the king’s death,” and showing that an alternative world (i.e. without the US) is possible, even if not desirable. It risks inadvertently making the America First-ers’ case for them, leading to a kind of self-fulfilling prophecy. 

Yet we are running out of time and excuses; the intellectual reckoning with Vance-type prescriptions for US military policy in Europe cannot be postponed any longer. If the Republicans win the White House in November, an unprecedented US pivot away from Europe could take shape rather quickly. We need to be ready to deal with that, and certainly to discern a bit more clearly its implications. Here is not the place for an in-depth analysis of the issue, but a few broad aspects are worth pointing out.

The headline numbers

It has long been understood that the aggregate military and economic potential of the European side of NATO alone is significantly greater than that of Russia. According to the IISS’s latest Military Balance figures quoted by ECFR, the Europeans (including EU states not part of NATO, plus Turkey) have roughly 6,000 tanks, 9,000 infantry fighting vehicles (IFV), 21,000 armoured personnel carriers (APC), over 7,000 artillery systems, and some 1.9 million regular active-duty soldiers across all services (with 1 million in the land forces). The Russians, in the midst of a war, are said to be down to about 2,000 tanks, 4,000 IFVs, 5,000 APCs, 2,700 artillery systems, while their regular troop numbers (across all services) are around 1.2 million, of which around half are in the land forces. 

By CSIS’s count (based on 2023 IISS data), non-US NATO allies have 8,500 tanks to Russia’s 3,300; 43,000 various armoured fighting vehicles vs 13,000 for Russia; around 7,000 artillery systems vs Russia’s 3,500; but are clearly behind on air defence (380 vs 567 Russian systems in the short range category, 221 to 970 in the long-range bracket). 

The IISS data seems to be under-estimating Russian equipment numbers. A recent RUSI analysis has noted that just inside Ukraine the Russians currently operate almost 6,000 artillery systems (of which, c.4,700 are classic barrel artillery while the rest are rocket artillery), 2,000 tanks and 7,000 IFVs – although this likely represents the great majority of Russia’s entire land force arsenal

While the exact numbers remain unclear, it is quite certain that, roughly speaking, the European members of NATO, collectively, have notably more tanks, IFVs and soldiers (double) than Russia; about the same number of artillery systems; and significantly fewer air defence systems (about one third of what Russia fields). In the air domain, a particular allied strength, the European outnumber the Russians two to one in very rough terms, when it comes to combat aircraft of various types.

The unit numbers

Since a contingency involving Russia would centre on land warfare, it is useful to look at the numbers of actual line units available to both sides, i.e. complete formations (brigades, of up to 5,000 soldiers) that could deploy to cover a sector of the front, as we see today in Ukraine. From this perspective things start begin to look rather different.

Again based on IISS data the European members of NATO have around 113 active-duty regular land combat brigades (excluding the 33 Turkish ones) – counting only the different types of armoured, infantry and air/amphibious assault or specialised (e.g. reconnaissance, special operations) brigades that operate as such. It’s a highly heterogeneous force even on paper, let alone in reality: a quarter of this number is made up of contributions of two or fewer brigades from the many small members of the Alliance. Only four European countries have more than 10 line combat brigades on their order of battle.

Interestingly, the Russian land forces (overall, not just in Ukraine) are estimated to also comprise around 114 line combat brigades (effectively the same as European NATO), when counted in the same manner – i.e. excluding separate artillery or other combat support and combat service support brigades and smaller units. To these may be added an extra 16 under-sized “volunteer” brigades, plus several dozens of individual line regiments and other formations. 

Even a very generic – and inevitably flawed – look at a more real aspect of the balance of forces would therefore indicate at the very least a rough parity between the European members of NATO (excluding Turkey) and the main Russian land combat force in terms of available formations. But there are three problems.

Firstly, as noted, currently the Russians have a clear superiority over European NATO allies in a few key equipment areas like air defence, electronic warfare and drone operations. Ammunition production and stocks also appear to favour Russia for now.

Secondly, the Russian military now benefits from the vital advantage of extensive battlefield experience. No amount of NATO wargames and exercises (however useful) can compensate for that.

Thirdly, the European “force” that would oppose Russia in a contingency would be a hodgepodge of very disparate units drawn from dozens of countries. The idea of “multinational formations” is purely theoretical: it has not been tested (certainly not on a large scale) in a high intensity warfare context in modern times, at divisional level. It has only been exercised, but in a very limited way. 

The US component

What about the American contribution to the European theatre? We shall leave the nuclear aspect aside, and assume continuity, given that the premise of the present discussion is only a potential reduction in US conventional presence. (If a potential second Trump administration tampers with US nuclear posture in Europe, the risks to NATO deterrence, and indeed survival as an alliance, are incalculable.)

Currently, the US has five land warfare brigades (Army “brigade combat teams”, to be precise) present in Europe. Unlike most similar European formations, the American BCTs are well resourced, trained and equipped, and add a disproportionate value to European defence.

In total, there are 83,000 US active duty military personnel deployed in Europe, of which only 26,000 are Army. The largest US military component in the region is actually the US Air Force personnel, numbering almost 30,000.

The strong Air Force emphasis points to what is considered to be a key US contribution to European defence: specialist airpower capabilities, both for SEAD missions (suppression of enemy air defences), dynamic targeting, and for ISR (intelligence, surveillance and reconnaissance, including from space). As the Libya campaign demonstrated already over a decade ago, only the Americans can provide the “enablers” like high altitude UAVs, air refuelling tankers, satellites etc (and indeed the skills, like targeting) required to fulfil these cutting edge missions – aside from unique strike capabilities like stealth bombers or electronic attack planes.

Not only the Libyan campaign but also the Ukraine conflict has showed that SEAD in particular requires complex airstrike packages that turn on the right kit, training and experience of such operations, which no European air force actually possesses at the scale needed.

Finally, and perhaps most importantly, the US provides the essential command and control element for the Alliance, both in terms of leadership and staff skills, and in terms of the necessary C4ISR infrastructure required to orchestrate large troop movements and operations in practice. In other words, the American military, through EUCOM and the NATO command chain (also under US authority) is the lynchpin of European defence. It holds together and brings some coherence to the myriad of different military establishments and defence inputs from the other NATO member states.

Caveats

Before concluding, it should be noted that assessing military balances is extremely difficult, and there is no suggestion that anything of the kind is being attempted here. But even for this (very general) discussion, as we try to make some sense of the prospects for European defence without the US, a couple of caveats are in order.

One is that we are looking at a moving picture. Both sides are building up their military forces and expanding their defence industrial bases. In March this year Russia announced a plan to form 14 new divisions and 16 new brigades, i.e. around 250,000-300,000 new troops in a total of 58 new brigades. This would fill the gap between Russia’s current armed forces size of 1.2 million and the 1.5 million target that former defence minister Sergey Shoigu revealed in January 2023. The addition of the new formations would also bring the Russian core combat brigade count to over 170 – and with the extra independent formations likely closer to 200.

But European military power is expanding as well, with the Polish army, at over 216,000, having recently become the largest among the continental allies and the country now pushing its defence spending to 5 per cent. All major European NATO allies are now buying new equipment as fast as they can (even from South Korea), from rocket artillery to missile defence and stealth aviation, while ammunition production is also being ramped up.

From a NATO perspective, the Vilnius Summit last year produced a new NATO Force Model. This is an agreement to boost the number of allied troops held at “high readiness” (across all types of forces) from the current 40,000 to 300,000, which may include as much as 30 land combat brigades. This will be extremely expensive and is unlikely to happen anytime soon, but it serves as a reminder of the scale of the challenge.

The second major caveat to bear in mind here, which works in Europe’s favour, is that there is no credible scenario in which Russia would launch a large scale war against NATO before somehow first neutralising Ukrainian military power. The great majority of Russia’s land combat force (some 500,000 troops, i.e. perhaps between 80-100 brigades) is deployed in Ukraine. 

Until the new set of approximately 58 brigades announced in March are stood up, there is no possibility even in theory of Russia attacking NATO, because it has no forces left for the job. Moreover, the bulk of the new formations will likewise be sent to Ukraine as well, in an effort to break Ukrainian resistance.

It is certainly possible that Russia could force Ukraine into a Korean-style armistice. This would still likely leave a sizeable Ukrainian army in place – perhaps around the current levels of some 100 brigades – that Russia would have to plan against, if it looks to go to war with NATO. Again, this would reduce the available forces for an offensive westwards into the Baltics or Poland. There is also the more extreme theoretical possibility of a total Russian victory followed by a “demilitarisation” of Ukraine per Putin’s original goal, but this seems highly unlikely to happen.

To sum up, there is hardly any reasonable scenario in which Russia is “free” to assemble even a 100-brigade force to attack NATO (assuming its ongoing military build-up succeeds in expanding the overall land force to 200 fully-equipped brigades), even if it eventually fights Ukraine to an armistice – let alone in the next two-three years. 

As for the idea that Russia would launch into a war with NATO hoping for a “quick win” in grabbing a bit of Baltic territory and therefore somehow collapsing the political will of NATO, this is a particularly inept notion whose enduring popularity within the transatlantic “strategic community” only illustrates the West’s intellectual bankruptcy in military-strategic affairs. 

Conclusion

There is little doubt that any NATO-Russia war would be very long, in the “fortunate” (and rather unlikely) case in which it doesn’t escalate to nuclear exchanges early on. The Ukraine experience should remove any illusions about the possibility of “quick wins” in 21st century large-scale conventional warfare. The Russians themselves have learned the lesson the hard way.

All this, coupled with Ukraine’s ongoing and valiant resistance, should provide strong reassurance against the possibility of Russia deliberately setting out to attack NATO in the foreseeable future – certainly not as long as the Russian armed forces are still overwhelmingly engaged in their current illegal war.

Even if Europe’s military power is arguably weaker than Russia’s in real terms (i.e. actual combat capability and battle ready formations), this matters little if the Russians are busy elsewhere. In this context, even without the 5 US brigade combat teams, the forces that the Europeans can deploy by themselves on the Eastern Flank would seem sufficient to offset and deter whatever “screening” formations the Russians have held back from the Ukraine front.

But the current situation will not last forever. Russia is building up its military and it may well neutralise Ukraine, one way or another. In the future it could regain the freedom to turn the bulk of its forces westwards: perhaps as much as 150 brigades, in a post-Ukraine war world, in which Moscow will have to keep significant forces in reserve around Ukraine. 

The Europeans must therefore use this breathing space – which might only last as little as three more years – to really accelerate their own defence expansion in terms of actual combat formations with all necessary support including ammunition and logistics. 

An adequate European-only defence that can achieve rough parity with that future Russian threat will likely require, very roughly, standing up at least 20 new fully equipped brigades (150,000 troops), and a rigorous programme of upgrading and exercising the existing c.113 brigades spread across Europe.

All in all, a significant drawdown of US land forces from Europe would not be a terminal event for the continent’s defence, if the Europeans get their act together and expand their armies by a relatively modest amount (around 10 per cent of the current regular troop numbers of all European NATO members excluding Turkey).

The most thorny aspect of a US pivot away from Europe, however, is usually considered to be the prospective loss of US “enablers”, from SEAD to ISR and air mobility. It is widely acknowledged both that Europe cannot cover this gap anytime soon, and that these types of capabilities are also very valuable in the Indo-Pacific so they are likely to go if the policy views of the likes of JD Vance prevail.

At the same time, though, it is worth asking to what extent are these unique US “enablers” so vitally important as we have become accustomed to believing. Indeed, it may be said that Ukraine’s successful defence, including in the air domain, proves that the Russians can be kept at bay with much less sophisticated technology than what America fields. It is true that the Ukrainian military has been receiving ISR data from US assets flying around its airspace, but there is little evidence that this has been a determinant factor. 

As regards air mobility – both strategic air lift and things like air refuelling – again Ukraine shows that a major land war in Europe will depend on ground based logistics (roads and railways) reaching to the front line. Air mobility is required primarily for rapid-reaction operations at scale, for example in the case of a surprise Russian attack, but that is unlikely to occur now that we have learned the lessons of 2022. 

As for air-refuelling capabilities for long-range air strike missions, again it is not clear whether this type of operation would make a critical difference in a war with Russia – also bearing in mind the proliferation of very long range air defence systems, and the geography of the European theatre. 

In final analysis, there is a strong case to be made that a reduction in the US military posture in Europe – in particular, the drawdown of Army brigades and Air Force assets, including the rare “enablers” – would not, by itself, doom Europe’s defences. Indeed, the US would still be able to provide extremely valuable support in the C4ISR dimension, particularly through its space-based assets, while nuclear deterrence would still be in place.

The main point is that, if Russia does manage to fully turn its sights on NATO with the intent to invade, the US military assets currently deployed in Europe – powerful and important as they are – will not make a fundamental difference either way. Nor can America be expected to increase its European military footprint even under a president Harris. 

In other words, Europe needs to significantly build-up its military capability in any scenario.  There is no escape from this large-scale defence imperative, but it doesn’t seem that this is yet properly understood by Europe’s political leaders – and we’re running out of time.

Gabriel Elefteriu is deputy director at the Council on Geostrategy in London and a fellow at Yorktown Institute in Washington, D.C.