I've always seen the main DC heroes as more heroic than their Marvel counterparts. Currently in Marvel's New Avengers the past couple years have focused on a plot where the Multiverse is collapsing due to the early death of a universe causing the multiverse to contract. The other universes in the multiverse are colliding into each other and the incursion point is earth. The situation the heroes keep finding themselves in is they blow up one earth it stops the incursion but if they fail to stop an incursion in 8 hours both universes are destroyed. So the price is sacrifice one earth to save two universes. Other methods have worked once or twice but no long term solution has presented itself and the Incursions keep reoccuring. Namor has destroyed one earth to save the regular 616 Marvel earth and has conspired with villains to destroy other earths to keep saving the 616 Earth from Incursions.

So in a similar seemingly no win situation what would the Justice League do different?