Axis and Allies 2nd Edition: to Pearl Harbor or not to Pearl Harbor
What the Expert Says...
In his excellent essays, Don Rae says Japan should always attack Pearl Harbor on its opening turn (see Essay #1):

The Pearl Harbor attack (this should be obvious to all players) should be conducted, always, without exception.
If this U.S. fleet is not removed, it will be used against you in the Pacific (non-optimal), or it can be driven through the Panama Canal to assist the U.S. Atlantic invasion front (optimal). Any anticipation of anything less than the optimal response movement from the U.S. player is generally considered as weak play....
Because of this, you must always use enough forces to take out this sea zone area decisively.

Don then goes on to describe what units to use, which depend on whether you follow his suggestions for &quot;basic&quot; tactical play or &quot;advanced&quot; play. In the basic approach, he suggests throwing everything you've got at it except for your transports. That is, you're going to send two battleships, your sub, two fighters, and the carrier.
If you use the advanced play, Don suggests a more muted attack:

1 battleship (Japan)
1 submarine
2 fighters (one from Japan, one from the carrier)
1 bomber

With the carrier stationed off Solomon Islands.