A modern-day game would run into a number of problems:
Controversy: Would you give Hugo Chavez a bonus or a penalty? Would China count as a Communist Dictatorship or an Emerging Capitalist Totalitarian State? The debates would be endless, and Paradox could well be opening itself up to charges of discrimination, not only from players but from countries.
Short shelf life: I used to love the game "Shadow President", a very detailed political, economic and military simulation set around 1992. Unfortunately, while time has moved on, Shadow President hasn't. It starts in 1991 when you have to deal with the Soviet Union collapsing and Iraq invading Kuwait...but increasingly that world seems absurd, and America's role different. Where are the environmental disasters and treaties? Where are the third parties acting as kingmakers in elections? Who in 2007 would have predicted the global economic meltdown of 2008-9? Who in 2000 would have predicted how 9/11 would change the Middle East and NATO? Within a few months of release the game would already be outdated, and within a few years it would be laughable - which means fewer sales.
Complexity: How could any game simulate the incredible complexity of the world of 2009? Consider all of the following and try to come up with rules for them that still makes the game fun: (1) Many third world countries are deeply in debt to the IMF and a large percentage of government revenues must be spent on debt repayments, even though regimes and even political systems have changed since the loans were made; (2) Agricultural producers in Africa face unfair competition from American, European and Japanese agricultural subsidies which are popular domestically and excluded from free trade agreements; (3) the First Past The Post system used in Canada, combined with its five mostly regional political parties, has resulted in minority governments for the last several elections. However, these minority governments do not act like European or Israeli minorities and do not form coalitions, preferring to act as if they had a mandate; (4) Thailand is coming under increasing international pressure to put an end to the export of endangered species, mostly to the United States and China.
...Basically, you could perhaps simulate the game well for the United States if you worked hard, but trying to make the same rules apply to every nation would be laughable. If you worked really hard you could get a game that worked well for Europe, too, but getting it to simulate the realities around the world would be next to impossible - and it would make the game too complex to enjoy.
