ISIS has claimed responsibility for the bomb that destroyed Metrojet Flight 9268.
If their claim proves to be true, the bomb appears to be of very familiar design and uses a beverage container to carry the explosive.
The first step on any action plan to safeguard aviation from similar attacks is to properly execute existing security measures. In this case, the 3.4-ounce or 100ml restriction on carried-on liquids should have stopped the attack.
As we consider additional security measures in the wake of the Metrojet and Paris attacks, we must first button-down what is already in place.