By a similar token, it can also be naive to expect the truth to be plain at the outset, or even for a sizable period of time afterwards. This is doubly (trebly) so for political matters (c.f. Gulf of Tonkin). What's sought is honesty.
To quote an old Murakami novel: "Speaking frankly and speaking the truth are two different things entirely. Honesty is to truth as prow is to stern. Honesty appears first and truth appears last. The interval between varies in direct proportion to the size of the ship. With anything of size, truth takes a long time in coming. Sometimes it only manifests itself posthumously."