It doesn't really matter about the content of the cables themselves, other than the immediate diplomatic embarrassment (and if an Army private in Baghdad was able to access this information, you can bet the Chinese/Russians/French/Iranians/anyone else has been reading US diplomatic cables for a long time).
Nor does it really matter about whether the United States is "indispensable" or not (worthy of a more detailed reply on US foreign policy, but this isn't Reddit).
The point is the long-term implication of governments being able to keep secrets. Of course, leaks are nothing new (for example, the Pentagon Papers). But if you have technology which allows instantaneous transmission and replication of data around the world, then governments will have a hard job of keeping secrets from their citizens except for very short periods of time. In the same way that that the internet is destroying the record business - despite their attempts to hold back the tide through legislation - the same technology is destroying the secrets business, both public and private.
Nor does it really matter about whether the United States is "indispensable" or not (worthy of a more detailed reply on US foreign policy, but this isn't Reddit).
The point is the long-term implication of governments being able to keep secrets. Of course, leaks are nothing new (for example, the Pentagon Papers). But if you have technology which allows instantaneous transmission and replication of data around the world, then governments will have a hard job of keeping secrets from their citizens except for very short periods of time. In the same way that that the internet is destroying the record business - despite their attempts to hold back the tide through legislation - the same technology is destroying the secrets business, both public and private.