Of course it's lying, but that's part of the great game. It's like salesmanship, which is another field often associated with dishonesty and lying.
The usual tactic is to warn people of the dire consequences of not engaging in whatever military action they want to take. It's the idea that "if we don't act now, the enemy will come and take away our precious bodily fluids!" Since most people don't want to lose their precious bodily fluids, they can be frightened into supporting whatever action the politicians deem best. They would see that as "trusting the experts," since they presumably know what they're doing.
A few people want to hear the truth, however ugly, but others want to hear only those truths which are convenient, while discarding that which is inconvenient.
There's the concept of doublespeak, where people might express the "truth" in different ways so as to not make it an outright lie, but perhaps to soften it somewhat. Such as terms like "collateral damage." I remember when the military made some report about a failed missile test where they said it didn't crash, but it "failed to fly." I read a book which had separate sections for military speak, legal speak, advertising speak. Advertisers like to use "weasel words" where they can hawk their product but not get sued for false advertising (and sometimes they still cross the line).
