My main problem with the article is that I don't believe this premise of the article is true:

The public would probably also be shocked to learn that funding perpetual war, unauthorized by either Congress or the U.N., is already against the law.

I want to say: got a link for that?

As to what Warren and Sanders support, that's actually easy: they are both U.S. Senators with voting records.

Further on Warren. Warren started her trip into public life as a consumer advocate law professor with clear moderate capitalist sympathies but feeling that the scales had been tipped to corporations and away from individuals. She was a specialist in bankruptcy and commercial law and started to fight for more rights for personal bankruptcy when they were being taken away (Consumer advocacy included a section at TPMCafe working with her students!) From doing that, she found out how truly awful the lobbying situation was with the federal government.

Ideologically, she's moderate and despite how the right and Trump characterizes her, is not the type to lead with ideologically leftist ideas. She's very pragmatist, very. Probably the thing she cares most about is representative democracy working. When she talks "the system" she means: clean up the lobbying system and everything should work as it is and representatives can represent the true will of the people they represent, and not skewing to special interests.

From that: I really doubt she thinks that the majority of Americans are isolationist peaceniks. I also doubt she thinks a lobbying group like AIPAC, or any other lobbying group with undue influence about what happens with foreign policy represents what the majority of the people want.

This is her passion and priority and why she decided to run for office. Not foreign policy and not even becoming president. She figures things like foreign policy, they are secondary, they will work out according to the majority will if Congress and the Executive branch work as designed and government is cleaned up:

within that picture, answering foreign policy questions is a distraction. She does not take the position that the president is an autocrat as to foreign policy, but rather would be checked by a Congress without lobbyist influence and vice versa.

Many might think that unrealistic and or naive. Regardless, I think she believes, and does not think it is unrealistic and thinks it is possible. And I think that from reading and watching her work and statements for more than a decade.