Why wasn’t the Trump campaign warned by Obama’s FBI that the Russians were trying to subvert the 2016 election? They were required by law to do this.
Because it was a lie.
Because it was a conspiracy.
It likely wasn’t a lie. It is what countries do in all elections to some degree. CIA is infamous for using all kinds of methods to influence elections and destabilize countries... Of course Russia tried to do it. We do it to them.