There is something wonderful about a team like Barcelona. One that just thumbs its nose at convention. That plays the game the way we all did at recess. That is all gas and no brakes. That think they'll be the ones who can do away with such accepted concepts as "rest defense," or "control" or "being in their own half." Perhaps the beauty of these teams is that their demise is never calm, never subtle, but always in an inferno that can be seen from another continent. Such was their loss in the Champions League semifinal to Inter Milan. This is what Neil Young was talking about.
Before this matchup, it was generally thought it would be something like an irresistible force vs. an immovable object, given the attacking prowess of Barca and the usually stout defending of Inter. Except Barca were quite resistible, in a way, in that they were always vulnerable with even the most competent counterattack. And Inter were very much movable, given the way their squad full of council elders was fading at the end of a long season.
But you don't have to be that stout defensively when the opponent's defensive plan is on the same level of Moe Syzlak crawling behind six inches of bulletproof glass to stave off a robbery, only to helplessly watch Snake nonchalantly hop behind the bar and empty the register.
Barcelona consider rest defense for cowards
Rest defense is something most managers pay extra special attention to. It's the shape a team takes with the ball that protects it in case it loses it. It's designed to have control and frame so that should the ball turnover, there aren't highways and runways to the goal on the counter. It's a failsafe.
Barca consider rest defense for cowards. Rest defense is for teams silly enough to ever lose the ball, much like a hangover is only for those silly enough to stop drinking. Rest defense is surrender, apparently. What's Barca's plan when they lose the ball? Up yours, that's the plan.
Which is how you get this when they lose the ball just outside their box in the 1st half.

Is that enough space for Denzel Dumphries to run into between the centerbacks? I don't know, maybe he could have gotten a humvee through there, not sure.
Well hey, that's ok. It was a quick turnover and Barca aren't really expecting Dani Olmo to get picked so clean and so deep. They'll recover, dominate the ball again, get their chances, etc. Except...

After Gerard Martin gives the ball away, Hakan ĆalhanaÄlu just has to make one pass and Barca are left with just two defenders behind the ball. Marcus Thuram must be wondering if someone accidentally slipped a dead rodent into his pockets, given the amount of space he has.
But it's Barca. They simply apply too much pressure for any team to hold out. They nabbed three second half goals, as Inter's decidedly aging lineup simply couldn't cope with the pace. That's the wager Barcelona make every game, no matter how big the opponent. They'll play at such a ridiculous fashion, so high-octane, that even if they give up a goal or two, the other side will wilt and Barca will find the goals they need. They got three to match Inter's three in the first leg. They got three to seemingly outdo Inter's two in the second. Yes Virginia, the best defense is a good offense. You can simply drive through your problems, as long as you do it fast and hard enough.
Well, except...

This isn't even off a turnover. This is from a punt from Inter keeper Yann Sommer. It's injury time of the second leg of the Champions League semifinal, and you're protecting a one-goal lead. Might you think about having, oh I don't know, more than half your team in your own half to protect it? Two minutes from the final? Pfft, that's crazy talk. Inter don't have the energy to get up the field! Don't harsh our buzz, narc!
I mean, why defend in injury time if you didn't in the previous 92 minutes? Being true to who you are demands total consistency.
Well, ok, fine. There's still 30 minutes to go, Inter are out on their feet, even four of their six subs they brought on are over 30, Lamine Yamal is getting a shot every minute and a half. Eventually one's going in, Barca are still going to the final, easy peasy.
Except, is anyone going to try and tackle a clearly exhausted Marcus Thuram? Is anyone going to get within two yards of Davide Frattesi in our own box? No? Ok cool.
Barca and their supporters will say it's easy to point to their "defense is so passe" ennui as the reason they won't win the Treble now, while taking another drag of a cigarette and looking for another Talking Heads song on the jukebox. We just don't get it. They might have a point. Lamal brought miraculous saves out of Sommer, hit the post, and missed one or two other chances that on another day lead Barca to a somehow totally reasonable 6-3 win or something.
Of course, the flip side is that Inter could have bagged more goals, simply by launching a couple more passes over Barca's maniacally high defensive line. After 210 minutes, it's hard to argue you didn't get what you deserve.
That's the lesson for Barcelona. It's tons of fun to push it to the floor, to never consider the consequences, to feel the rush of watching team after team in front of you break. To cause destructions and leave the smoldering wreckage as someone else's problem. But if you never slow down, if you never turn, if you never see the road ahead that well, eventually there's a cliff's edge.