The government has to narrowly tailor criminal statutes to comply with the Constitution. It can't write them broadly, prosecute with discretion, then defend a dangerous law on the basis that their judgment in enforcing the law should be good enough for the courts.
When the government can argue that lying is generally dangerous to the common good (and therefore punishable by a fine and/or prison time), our days of speaking truth are numbered.
Churches, pro life groups, climate change deniers, and many more will be silenced for good if the 1st Amendment isn't protected.
That said, nothing in the Constitution prevents prosecution for fraud.
Still don’t see how you equate misrepresenting ones military background and military honors with free speech.