Lionel Messi.

Now there's been a long, ongoing myth that Lionel Messi is only successful due to two of the greatest midfielders to ever grace the game.. Xavi and Andres Iniesta play in the midfield behind him and supply him all the time with assists? Sounds silly, right?
Now some people do have a point that he struggles in Argentina's side because his goal record isn't as prolific for Argentina as it is for Barcelona and there has to be a reason for that, which is what i'm going to try and explain.
Barcelona have made the "tiki taka" style of playing their own throughout their first team all the way through to their academy, otherwise known as total football which was played by the Holland team as far back as 1970 which was led by Johan Cruyff and the national team coach at the time! Now Pep Guardiola has stated himself that Johan Cruyff has taught him a lot when it comes to football and it's no coincidence that since Pep's arrival at Barcelona as head coach and Johan Cruyffs's placement in Barcelona's backroom staff that Barcelona adapted the "tiki taka" as their own style of play and soon it made it's way into the National team and is widely credited for Euro 2012, World Cup 2010 and Euro 2008 trophies that Spain have won since.?
Now, back to my original point about Lionel Messi and the two Spanish maestros..Messi doesn't struggle as such when he's in Argentina's squad, he just doesn't perform as well as he does for Barcelona and that's because Argentina do not play total football, no disrespect to Argentina's style of football however but they do not base their style of play to benefit Messi which is something Barcelona near enough do.
Having sacrificed some of the worlds greatest footballers and playing them out of position to benefit and get the best out of Lionel Messi, the likes of Samuel Eto'o, Thierry Henry, Zlatan Ibrahimovic and David Villa .. Messi is basically given a free role within the team to pick up the ball whenever he pleases and run at defences once the said defences have been carved open with Barcelonas tiki-taka football.
The whole of Barcelona's team play to benefit Lionel Messi and that's not to criticize him whatsoever as he is a magnificent footballer and the team trust him a lot to basically give him the ball at any given opportunity as they know nine times out of ten, the ball will end up in the back of the net.
Now i believe myself that due to the small amount of tall players in Barcelonas team, this is why tiki-taka is so effective for Barcelona and Spains team, they have height where it matters in the team however in Xabi Alonso, Sergio Busquets and Gerard Pique in Spains team specifically.
Football's a very simple game, well.. it's as simple as you make it. Unless Argentina make some progress towards their international team playing Barcelona's style of play, they will simply not get the best out of Lionel Messi which would be a crying shame as a player as good as he is should be winning plenty of international honours around this time in his career and it would be a shame for him not to win anything with his country and people will always find that a reason as to why he's not "the greatest ever" or "the best in the world".