With the American people rightly aware of how tough it is to get out of foreign entanglements, they know that a test is ahead to fulfill President Barack Obama’s pledge of “no safe havens” for terrorists.

The direct threat of the Islamic State extremists to this country is not great, but the fragile nature of the Iraqi democracy and the complication of the multicornered conflict in Syria make this a considerable problem — and one that will make any response by the United States more difficult.

If it is not straightforward in the military sense — an array of forces, ours and allied, might be needed — the moral statement of the U.S. position is clear. “We stand with people who fight for their own freedom, and we rally other nations on behalf of our common security and common humanity.” That includes the people of Great Britain, who lost another hostage to the Islamic State murderers last week.

We hope that events, always unpredictable, justify the president’s confidence in a decisive result against this new extremist threat.