Ah yes ... conscription for our kids too
I'm sure you'd be the first to sign up.
Russia will always be our neighbor and it will always be hungry for land (the only thing that keeps such diverse population most of whom living in poverty, is their pride of belonging to a country whose military prowess terrifies everyone. That military prowess can only be tested through war). On top of that no one wants it to go tits up. That's because a fragmented Russia is the stuff of nightmares. Can you imagine were the mountain of nukes they have would go given such circumstances? So Russia will never go away. What can go away is the US's support who have a tendency to occasionally go full isolationist. The US had already made it obvious that their no 1 priority is Asia. The Israeli war vs the Ukraine war showed that given the choice they'll probably choose Israel over us as well. So can we really depend on such partner?
Now what benefits an EU army has
1- An EU army brings loads of smaller armies (Germany 181k, France 118k, Poland 292k etc) under one banner. Thus there's a smaller chance of conscription given this situation.
2- There's a myth that the EU doesn't spend enough money on military. That's silly considering that we are the third highest military spenders and we barely ever at war anywhere (bar the UK but they are not in the EU). The issue is not military spending but waste. To give you an idea the US has 1 main battle tank while Europe has 17. Overall, the US has 30 separate types of weapon systems versus 178 for the EU. Each weapon system is costlier both in terms of actually buying them and its ammo (economy of scale), it needs specialized people to operate and maintain etc. That goes away with a well coordinated EU army.
3- It will make us less dependent on US support which is massive but can be unpredictable especially if nuke threats are involved (will they swap New York for Warsaw, London or Dublin?)
4- It will allow the EU to shape its foreign policy. For example is it within our interests to get bogged down in Taiwan? Can't a deal be made with China were we close our eyes on Taiwan in return of them keeping Russia at bay? China is no friend to Russia. Sure they hate the US more but we're not the US right? Meanwhile shouldn't we have a tougher stance on Israel? Should we always toe in line to the US foreign policy? Are we allowed to think with our heads for once and act accordingly?
5- It will reignite interest from the military industry to invest in Europe. That will bring new business into Europe but it also plays a key role in ammo supply. The Ukraine war is burning ammo like crazy and all European stock (cause of 2) is at a all time low. If there's a war in Europe then we need to be able to produce ammo ourselves.
On top of that and the most important point is that the Russians hate losing. Their country tolerate almost everything but not an humiliating defeat. Thus an organized Europe will keep Putin and his ilk at bay
That's not me saying it but the likes of General Capitini and Graziano.