Difficult to see how if 1 and 3 are lies, then 4 isn’t also a lie. Either they’re dealing with a threat, which is something to worry about, or they’re not but are nevertheless lying to the public, which is something to worry about.
That doesn’t imply that if 3) is true that it’s not a threat.
Although, haha, now that I read again, my original conclusion is wrong. If 1) and 3) are lies then that means the drones belong to the USG and they know it. Therefore that would mean that the drones really aren’t a threat. At least not to the USG.