OK, the flawed logic is obvious i.e. a UNSC resolution that "condemns settlements" simply isn't an attempt to "resolve the conflict" i.e. it ambition simply is not that grand. It is what it is i.e. a definitive statement on the legal and political consequences of Israel insists on building settlements OUTSIDE OF THE NEGOTIATING PROCESS and, therefore, it should be something that the USA should actually support. This UNSC resolution would get everyone - Israel included - on the same page regarding the legality of settlement, and getting everyone on the same page has gotta HELP the chances of a negotiated peace, not HINDER it.
U.S. defense contractor accused of copying secret military documents (Reuters)
from the article: U.S.: Possible UN censure of settlements 'not helpful' to peace process