What was wrong militarily?
1. There were no airpower assets in Hawaii other than the heliocopters that were destroyed. That is probably not true.
2. There were no troop ground assets to assault the mountain top. Hawaii swarms with troops.
3. There is no way in God's green earth you could get the battleship moving in that time frame. Nor do museum ships have live ordnance on them. Even with the codgers, they did not have enough crew.
4. The aliens had NO defenses against missiles. Not realistics for warships. Nor could those geniuses figure out how to avoid a sattelite on the way in.
5. The three warships had about 270 missiles on them - they could have salvoed them at first action and ended the movie then.
If the international fleet had been inside the zone or the bases had a touch of warning, they would have destroyed the aliens in a short time. As it was, one destroyer took out most of the alien fleet. Given that the tech now will be examined, another sortie like this would be eliminated in no time.
The aliens main weapon, the shredders were taken out easily by jets. An alert defense would stop them. As far as the pegs. They seem a short distance weapon and if the ships had more AA assets, like more CIWS - they could have stopped them. Our ships are undergunned for saturation attacked with something like a mortar.
We could move to a distance as our missiles have much more range. True, radar didn't see the enemy but I'd bet IR and enhanced optics would and could guide missiles directly. The tech is well known.
They were the weakest aliens we've seen invade recently.