Charge or Intervene macro

I'm sorry but it's not possible to do such a thing with a simple macro.

Best you can do is probably a macro to charge if your target is an enemy, or intervene if your target is friendly instead:
/cast [harm] Charge; [help] Intervene; [target=mouseover, help] Intervene

Once upon a time a very (ahem…) wise Murloc had this to say on a thread about a similar subject:

24/01/2013 15:56Posted by Taepsilum

"If" conditionals and some sort of "while" loops used to be possible to implement with macros in the past (very distant past…), it was a design decision to disable these kind of options as they allowed players to automatize most of the decisions that we think should actually be a core part of the gameplay experience.