Language and politics have always been linked, and today there remain many examples, no less in the Middle East and the War on Terror.
Peter Beinart recently asked why Israelis insist on pronouncing Hamas using the Hebrew "chet" sound, approximated by the Spanish "J", as in Guadalajara, or the "ch" in bleccchhhh. In Arabic, "Hamas" is spelled and pronounced with the more challenging throatiness of the letter 'Haa. The Hebrew Chet is still pronounced that way by some Jews of Mideastern origin, but standardization of modern Hebrew has largely eliminated that. So, there's one easy explanation.
On a more complicated level, though, this also fits an Israeli and Western optic, where "we" get to define others on our terms. Hence, some of my colleagues in the pro-Israel community still use the antiquated "Moslem" to refer to Muslims, akin to calling Beijing by its erstwhile, anglicized form of Peking. Like the duck.
When I see someone of this century referring to "Moslems", I immediately sense a lack of understanding or sympathy for a religion and culture of one billion souls, spanning dozens of countries. It's almost as quaint as Thomas Jefferson's vintage reference to "Mussulmans". Unlike "Hamas", the Arabic "Muslim" easily lends itself to correct pronunciation by English-speakers. At least, for those who care.
Saying "Hamas" with a simple English-style hard "H" sounds more accurate, since it leaves out the guttural -- and completely wrong -- "kh" as in Guadalajara. Knowingly or not, pronouncing "Hamas" as a modern Hebrew term, rather than the Arabic of its origin, takes ownership of that group's narrative. It really displaces the broader Palestinian narrative, as well. In fact, most Israelis still refer to Palestinians who are Israeli citizens as "Israeli Arabs".
When pro-Israel activists in the States hear an Israeli expert refer to "Chamas" (or "Khamas"), they may assign more authority to the analysis and arguments, since few Americans can pronounce that sound, either. Of course, that same word in Hebrew, with the Chet, translates as criminal violence, so there's also that.
We are admonished to call evil by its name, but if we insist on pronouncing it our own way, how does that help the fight? The world, and sometimes our own neighbors, don't operate according to our fears and expectations.