You would have thought that our government would have learned when they attempted to ban PGP, decades ago.
For those of you who don't remember, the software got classified as a munition, people who sold it could be arrested as arms trafficers. Downloads instantly moved from US servers to those in Finland (and elsewhere) and the end result was a big spectacular nothing.
Calmer heads prevailed, in the long run.
The technology is out there, the knowledge of how to do encryption is impossible to stuff back into the bottle.
Yes, I remember the bad old days when a Netscape web browser was considered as a weapon of war and it was illegal to export it outside the US and there was a check box on the EULA saying you agree that you wouldn't export it.
If ITAR is again applied to encryption then the US will stop being able to sell pretty much any technology overseas and most people in the US who aren't complete morons will just import hardware and software from free countries where encryption is allowed.