When asked what books/magazines/newspapers she regularly read Sarah Palin couldn't name any and when pressed by Katy Couric she said "all of them".
Gary Johnson asked "what is Aleppo" and couldn't name a world leader whom he admired
Trump said Russia would never go into the Ukraine. It already had when he said that.
Hillary didn't know that "C" meant Confidential or that she shouldn't have a private server in her home or delete emails
This picture is the best I can do to convey my feelings.
How much that candidate ought to know about foreign and world affairs
is a question that cannot be answered because it can never be too much,
even though the president has an army of advisors around him!
It's a bit like asking how intelligent the person should be.
Pieter Bruegel here depicts the subject of the blind leading the blind literally.
They all end up falling into the ditch.
The painting is also a study of the different stages of falling and the expressions on the faces range from trust to surprise and shock.