I predict us winning treble as it happened both times after Messi did not win WC previous summer. He will be hungry and motivated especially in CL.
Think we have now have critical mass of new top talented players, who are yet to win the competition to compensate for those who have "won it all" to keep us fresh until end. Effect and desire we will get from Coutinho/Dembele/Malcom/Vidal/Semedo/Arthur/Umtiti will surpass the passiveness of Busi/Pique/Suarez/Alba/Messi in final stages.
Agreed that we may very well win the Treble (or the European Double, at the very least). Every time we've won the Champions League we've always won the league title too.
Only one of the Trebles (isn't it amazing that we're even able to say this in the plural? Madrid hasn't ever come anywhere near a whiff of one) was after a World Cup (the 2015). The first one was in 2009.
That Barcelona 2009 team, incidentally, played the Most Beautiful Football ANYONE had ever seen. Of this there can be no doubt.
Madrid was able to win successive Champions Leagues because they PRIORITIZED the competition, not being able to compete with us domestically. That was the only thing they could do to salvage their campaign last season and years prior.
Just going by head-to-head results domestically in El Clasico, we would have overwhelmed Madrid in the Champions League had we faced each other. Even in a one-off game. The gulf in actual quality between us and our eternal rivals is vast.
I'm not saying that winning the Champions League in 2018-2019 is a forgone conclusion but you can be sure that Messi and Barca will be extra motivated to win it this season.
Now everyone and Madristas will see just what it's like when we prioritize a particular competition. The only team that can beat us is ourselves. A cliche but it's true.
"We cannot go one more year without winning the Champions League".