This match just proves that you can't get by with a good defense in football - you have to have both good defense and attack. USA, Iran, Greece, and some other teams all have very good defense, but their lack of good offensive potential is their ultimate downfall.
I dunno, Greece and even the US have good enough potential in the offensive in my view, but they both made too little use of it. I agree though that this world cup showed that you can't get by by just concentrating on defense and waiting for mistakes of the opposing teams. All the teams that traditionally do that are out now: Italy, Greece, Portugal, USA.
This is mainly because soccer particularly in the offensive became a much faster game during the last 15 years. Offensive players steadily change their positions basically forcing the defending team to play zone defense instead of defending one to one and close to the opposing player. The steady and often unpredictable movement of nowadays offensive players makes it practically impossible to prevent attempts at goals.
I remember that just 10 to 15 years ago the game was a lot more static. It was about fast players on the left and right side that try to overrun the defensive line and put in a cross toward high strikers that are strong with the head and it was about one central creative player trying to shoot a clever pass into the penalty area to serve a striker. It was all in all a lot more predictable and the defensive players always faced the same opposing player when defending.
That was when teams like Italy or Greece through their very good defenders were able to practically destroy the opposing team's offensive game. They would give the opponent just two or three opportunities for scoring goals at max during the whole match. They did not really manage to do that this year.
....thanks 
Made it further then i expected, im proud of them