I don't ask this out of hostility, but I wonder why Mr. Walls and Cardinal Martino saw fit to make these statements. Did they (specifically) make them when that Dutch doctor published his piece (in, I think the New England Journal of Medicine or JAMA) proposing an infanticide protocol? Did they speak this time because a reporter asked them? I'm surprised that such high Vatican officials would see fit to comment on this, and I wonder if it has anything to do with how they see the influence of the US in world affairs.
The difference is that a recommendation of protocols is just that, a scholarly abstraction.
In this case, a flesh and blood human being was purposely deprived of water until she died, and the state did nothing.
The Vatican is re-asserting a continuous, consistent policy of protection of innocent life.
I don't know why, untenured, but I'll give you this prediction: you will see a majority of states quickly revise their laws to more carefully define "living wills" and what constitutes "life support" or "heroic means," and I personally think it will be on the more liberal side of these definitions rather than the conservative side. In other words, I'm betting feeding tubes will be considered "heroic" measures more often than not.