Why such a history of defending islam here at FR then?
We all know why.
taqiyya
muslim scholars teach that muslims should generally be truthful to each other, unless the purpose of lying is to "smooth over differences."
There are two forms of lying to non-believers that are permitted under certain circumstances, taqiyya and kitman.
These circumstances are typically those that advance the cause islam - in some cases by gaining the trust of non-believers in order to draw out their vulnerability and defeat them.