Fanatik,
Dunno if the Russian force is defensive – it's increasingly used as an expeditionary warfare force. It's actions in Ukraine were very much offensive.
I don't think there would be a war of attrition against the west. I suspect any Russian offensive action is predicated on achievable targets (eg Crimea but also Baltics), and quick offensive action.
Europe itself doesn't have the capability to wage an attrition/protracted war simply due to the fact so much military infrastructure has been gutted. Not just units or bases or equipment but the industrial infrastructure to go with it.
Europe arguably doesn't even have the capability to wage a short defensive war – remember a huge chunk of Europe's combat power is situated within Greece and Turkey. With proposed cuts to British forces it will gut capability significantly.
Europe's lacking in a lot of areas:
1. Conventional combat units including armour and artillery as well as long range strike.
2. Strategic airlift and overall transport capability.
3. Electronic warfare capability
4. Modern equipment (most of Eastern Europe's combat capability is still stuck in 1980s or worse).
5. Munition stocks – highlighted in Libya when some partners pulled out quickly due to lack of munitions. This has not changed.
6. Ability to sustain losses. The reserve forces in a lot of countries have been reduced to poorly equipped light infantry. There are no more reserve pools of heavier equipment.
7. Layered air defence – many European states lack any kind of medium to long range air defence and those that do are equipped with now obsolete systems – MIM-23 Hawk, 2K12, 1980s vintage S300. Patriot or equivalent is only in use with a small number of operators in limited numbers (Netherlands, Germany, Greece, Romania, Spain and now Poland) and often in small numbers (single regiments).
8. Lack of air dominance capability – US F-22s really are a game changer and F-15C/D still better than most of what is in service in Europe. The acquisition of the F-15EX seems to indicate F-35 doesn't match an upgraded F-15 in combat even with supposed stealth advantage.
And hitting here is also decline in hours flown by many European pilots (even French were struggling to get over 100 hours per annum a couple of years ago).
9. Lack of maintenance and sustainment capability. Many countries are struggling to maintain spares now in peace time! As such serviceability is really, really low across all spectrums of warfare be it aircraft or submarines or tanks or trucks.
10. Lack of training capacity to induct large numbers of troops.
11. Lack of ability to combine logistics due to lack of unified procurement. This is a big advantage for US and Russia. Eg whereas those countries might operate 1 main assault rifle, the Europeans operate numerous different types from AR-15 types to AK-types to Heckler & Koch G36 to Beretta ARX160 to Bren CZ805.
Or artillery – European NATO has numerous different types and in multiple different calibres – 76mm, 100mm, 105mm, 122mm, 130mm, 152mm 155mm, 203mm. And on numerous types of platforms – Panzerhaubitze 2000, AMX 30 AuF1, CEASAR, KRAB, M109, M110, M114, M115 2S1 Gvozdika, MT-12, D20, D30, GIAT LG1, ZUZANA/DANA, TN90, M82, AS90, L118, FH70, OTO Melara Mod 56, Panter ETC. Often these are in service in numbers as low as 12-18 pieces.
That doesn't include rocket systems which are ironically mainly of the Soviet 122mm variety but which are based on numerous different types of trucks (various versions of Tatras, Urals, Jelczs, DACs) which makes it again problematic from a logistics capability.
Compare that to US: M109, M119, M777. Calibres 105mm and 155mm
In itself it's not a problem if each state is able to supply large number of troops and keep them sustained. But a massive problem when numbers are low and ability to replace is low.
12. The big one – most NATO partner states have only token militaries and lack capability to deploy much to support partner states without completely disarming themselves. Eg if Czech Republic deployed 30 tanks and a squadron of fighters to the Baltics, it would have no armour or fighter capability left in the Czech Republic! Same for Slovakia or Portugal or Croatia or Denmark or Belgium (especially with fighter fleet scheduled to decline to a mere 34).
The US can wage attrition war against the Russians but that would considerably weaken their position overall against the true elephant in the room, China.