Use of the word "cables" for diplomatic emails - is this good English?

I was reading this article
Obama wants more Afghanistan options - President wants revised choices after plans produce dissent among White House team

and came across this

A “cable”? What is this, the 60’s? Do they have an on site telegrapher? It sounds clunky, but is it good English?

For all intents and purposes a telegram sent by international cable isn’t any different from an email sent by the same means except for the protocol being used. The word “email”, however, doesn’t come across as being as official and weighty as one could wish. Calling an official document that was sent via email a “cable” seems like a perfectly reasonable thing to do as a shorthand for its importance. The term is dated, lending it a certain weight that matches what is needed.

‘cable’ is a perfectly good word to mean an electronic text message. electronic messages can be sent by satellite, coaxial cable or fiber optic cable.

we still do dial a phone number as well.

It seems to me that “cable” meaning a particular type of diplomatic dispatch is simply an extension of the original meaning “telegraph message,” and can be legitimately applied in the former meaning to an e-mail.

It’s no different from referring to e-mail messages as being “c.c.ed” even though it’s obviously no longer an actual carbon copy, or referring to something as a “film” even though it was entirely shot digitally.

If he said “email” then StarvingArtist would complain that he broke protocol. Sometimes you can’t win.

Well, let me be clear. I’m assuming these are either emails, or scanned PDFs of actual signed and printed letters sent as email attachments over whatever secure encrypted data lines the US uses, but they are still emails correct? No one is carrying a printed letter via Diplomatic courier pouch as the delivery method or using a TELEX… right?

Hmm…Yes, they do. And with those now odd-looking wax seals on them, even.

Still? Wow.

They kind of are and kind of aren’t emails. A cable is a message using a distinct and regulated form. It isn’t like someone sitting down at Outlook and pounding out their thoughts in Gmail. There’s many examples of the form of a cable, just google “state department cable” or something like that.

So the term cable, which is used very specifically within government to denote an electronically sent message that carries with it the form and function of an official bit of correspondence from or among the State Department and our embassies. Email is also used for communication, of course, in the same way that everyone uses email, for messages that are urgent and directive to “where do you want to have lunch?”

So in that sense, your question focuses on the term “cable” as a means of transporting a message, whereas folks in government focus on the term “cable” in terms of its official form and function, regardless of how it is transmitted. The words could be interchangeable in one sense, but as they are used, the difference in government is quite clear; like if I was talking about a “puppy,” everyone knows that a puppy is like a dog, except it has special characteristics that mean that not every dog is a puppy. In the same way, a cable is like an email, but not every email is a cable.

Cables are sent by special, secure electronic channels that operate like the Internet, but are not the Internet that we use.