It's not a problem that Islam views all other religions as heresy. So does Christianity.
The major problem is in Islam's militant attitude towards other religions.
A lesser but still significant problem is that Islam is able to conduct missionary and political activities in Christian lands, while protecting their base from Christian missionary activities. This asymetrical playing field needs to be challenged.
Reciprocity ought to be demanded, and in an earlier age we would have. But the West has lost all interest in the Christians in Muslim states.