The Muslims are united in their faith against the West. The West has become a house divided: people of Faith and secularists. The people of Faith recognize that the Muslims see us all as the enemy. The secularists group the Jews, Christians and Muslims as "religious nuts" so they're against religion. They erroneously believe that secularism is the true way of preventing a Muslim takeover. But if you want to know the results of this thinking, look at France.
Sorry, wrong answer. The left fully understands the dangers Islam poses to their way of life. However, they have a bigger enemy to deal with first: Western Civ/democratic capitalism.
Hitler signed his pact with Stalin so that Germany could first focus on the Western front. So too do liberals hope to take out Western Civ, thus creating the new socialist man, before they turn their attentions to the Islamic threat.
The entire thrust of the Dem's anti-war logic is that it's "our fault" ie the West's history of exploitation has caused turd-worlders to "hate us". This strategy to upset America's war effort & take back political control is NOT based on some naive assessment of Islam.