The first thing we do it fire all the Arabs...

Report:

A leading haredi spiritual leader and halachic authority ruled this week that due to the potential danger to Jewish life, it was forbidden to hire Arab workers, according to Yom Chadash, a new ultra-orthodox daily.

Rabbi Haim Kanyevsky told yeshiva administrators, "We are war with them [Arabs]," therefore "according to Jewish law it is prohibited to hire them," according to Yom Chadash.
Yeshiva administrators, after the Mercaz Harav Yeshiva attack, asked Kanyevsky whether they should fire their Arab employees.

Kanyevsky, who expressed surprise that Arab workers were preferred to Jews, asked, "Are there no Jews who can work and earn a living from the same work?"

He said that under normal circumstances it was always preferable to hire Jews rather than Arabs, unless there was a significant difference in cost. But in the present situation, due to the danger to Jewish life, there was a prohibition against hiring Arabs, he said.

Kanyevsky's ruling is likely to result in a mass firing of Arab employees at hundreds of haredi yeshivot across the country.

Some rapid responses:

1 - You can't hold every Arab in the world responsible for the behavior of a few lunatics.
2 - Arabs have been working in yeshivot for generations. How many times have one of them gone postal? (I honestly don't know.)
3 - Is dismissing hundreds of workers, and depriving them of paychecks, and possibly food and shelter, too, going to make the situation better or worse?
4 - If Rabbi K honestly believes that Israel is in a state of war, how does he justify keeping the yeshivot running at full capacity? If Israel is at war, shouldn't those haredim who are less than average learners be in uniform?
5 - Why is it "always preferable to hire Jews?" I understand this is a long-standing halacha, but where does it come from? What's the reason behind it? Is it simply the chosen religion's way of protecting its economic vitality? Or is there something else behind it?