Three dolphin-class submarines are not game changers even if they have secret nuclear capabilities. The addition of David's Sling Weapon System is also not going to create a panacea when it comes to defense.
Power today is measured in terms of soft power, especially trade. Israel's bright spot is its UAV market, they sell lots of them, they invented them. Outside of the defense market it is generally among creditor and debtor nations where the real power plays are occurring now.
The days of who has the bigger guns is over, urban warfare and guerrilla warfare is the new game, not huge pitted land battles. While Israel cannot be taken, neither can she take her neighbors, not even America could take Iraq or Afghanistan.
Some of you guys are stuck thinking like this was the old days but the world especially when it comes to defense has moved on.