The last thing we need, and possibly even want, is to wait for international support, much less consensus. If we want sterile justice, we need to identify who did it, capture them, try them, and convict them. If we want revenge, we need to identify them and kill them.

But if we want to try to prevent this from happening again, now that the world has seen how easy* it is to do, we need to retaliate with such an overwhelming response that not only will potential agressors think twice about trying us again, but also their host countries will decide that the risk isn't worth the reward. The Taliban may be thrilled at what has happened, but if the reaction is to flatten their country, they might, in the future, impose limits on what their pet "rogue elements" will do.

* Relative term, as compared to launching a nuke.