US carriers near Pearl Harbor were not ready for an immediate counterstrike

Could US carriers have counterattacked the Japanese force immediately before Pearl Harbor?

Only with difficulty; their position and loadout were unfavorable, and they still needed reliable scouting and contact.

The carriers were returning from delivery missions and were not necessarily positioned or fully loaded for a strike. Knowing the enemy is nearby also does not reveal his exact intent, so scouting and continuous contact remain essential.