Threat assessment will show its defenses were overwelmed by the macguffin weapon. Maybe even conventional missiles - these things aren't invincible.

The normal Carrier travels with 12-15 destroyers and other auxiliary vessels to provide screening and defense overlapping. If the carrier is struck and damaged/sunk in the center or back of this strike group, without loss of other vessels, an immediate retreat and Threat assessment will be done to see how the macguffin weapon got past everything else. This would be the concern - again Carriers aren't invincible, but how your macguffin got past so much radar would be important and the MAIN focus, if the macguffin did not do it in an immediately obvious way.

If the entire strike group is damaged/sunk, the entire fleet will pull back to begin assessing risk of the macguffin. Damaging a fair number of ships run by the United States in a short order should be beyond poor nations capabilities, so the macguffiin weapon would necessitate reevaluation. Delay of at least a week to assess where/what the macguffin weapon is, (Assuming its a singular object) and then if the target, say Iran, is able to be struck within a specific loss ratio of troops.