Why did the Mueller terms of reference only target the Trump campaign and Russia? Just days later CIA director John Brennan admitted under oath to Congress that other countries attempted election influence. Brennan resigned in Jan 2017 so knew before. nytimes.com/interactive/20… 
A proper terms of reference would have referred to "election links and/or coordination influence" without naming a country or campaign. The terms of reference protected at least one other country, according to Brennan's admission--and possibly the Hillary Clinton's campaign.
There is evidence that Ukraine, the United Kingdom, Saudi Arabia and Israel were engaged in influence operations and possibly a number of other states. Which country is being protected by Rosenstein? Why is that country, or the campaign it is connected to, above the law?
