In the 1990s, in what became known as the Crypto Wars, the U.S. tried to limit powerful encryption — calling it as dangerous to export as sophisticated munitions — and eventually lost.

After the 2013 Snowden revelations, as mainstream technology companies started spreading encryption by putting it in popular consumer products, the wars erupted again. Law enforcement officials, led by FBI Director James Comey, loudly insisted that U.S. companies should build backdoors to break the encryption just for them.

That won't happen because what these law enforcement officials are asking for isn't possible (any backdoor can be used by hackers, too) and wouldn't be effective (because encryption is widely available globally now). They've succeeded in slowing the spread of unbreakable encryption by intimidating tech companies that might otherwise be rolling it out faster, but not much else.