I seriously doubt that: chess is unique because its probably the most complex game that everyone knows how to play. However to prove the point I'll need take a step away from chess for a second and look at a similar, but far simpler game: checkers. Checkers has no luck and simple rules, it makes it easy to play, and the lack of luck makes it, in theory, a game for intellectuals. However there are no pro-checkers games. The biggest difference between checkers and chess intellectually isn't the simpler rules, but that pro-checkers is unwinnable. There is a series of moves, where you can employ the exact same opening strategy and you only need slight variations after that based on your opponents moves to make you unbeatable. If you play the right strategy the best your opponent can do is draw with you. If two players are smart enough and have played enough games, the game will end in a draw.
Chess isn't there yet. The first few moves are normally identical game to game, however after 3 or 4 moves, there isn't one statistically superior move, every other move has a counter and its all about out smarting your opponent. This is what makes chess so special, there is no unbeatable strategy, and there probably never will be (given how many pro-chess games there are every year). Some strategies fair better then others, but the same move will only beat so many opponents before someone counters it. Prochess games aren't what blanflag thinks they are, because you have to adapt your strategy and you have to be creative and unpredictable, as well as calculating of possible moves, which does require some memorization.
So the question is, is diplomacy more like chess or more like checkers? Its more comparable to chess, which granted is the argument you make. But that's because of two reasons:
1. The diplomacy element. Every game is different because different people make different alliances for different reasons. There are statistically strong alliances, alliances that fair better then others. The Juggernaut, and how it use to dominate play, is a good example of this.
A really talented Austria-Italy can stop a juggernaut by itself, but normally it doesn't have too because Germany and or England will attack Russia whenever there is a juggernaut. However Austria when facing a Juggernaut, assuming diplomacy isn't an option wins or loses not based on what is statistically the smartest move but based on:
2. Simultaneous turns: As Russia you have an army in Galicia, Austria has an army in Budapest and no other armies near by. As Austria do you bounce him in Vienna or hold in Budapest. As Russia do you move to Vienna or Budapest? Predicting where your enemy is going to move means there is no perfect choice.
Some players look at what is the statistically smartest move for their opponent, and assume thats what they'll do. Others assume their opponent will do the opposite, others flip a coin, others look at past moves from their opponent to look at patterns. Others may have some other method of deciding 50-50 choices that I am unaware of.
This aspect is what makes every game unique, its not like chess or checkers where you can't react to a players moves because the moves happen when your moves do.
Simultaneous turns also means that you can't tell whether or not someone promising a support is lying or not, it means a lot of things, this was just the easiest one to explain.
It is those two differences that makes every diplomacy game unique, not the fact that its like chess in which there is no 'smartest' strategy.
Diplomacy has stalemate lines, and every pro-player, when losing a game, has a clear vision as to which of them are attainable and which are not. I'm not saying stalemate lines are absent from variants, and nor should they be, but its a hard truth that in diplomacy there is such thing as a perfect strategy (the simultaneous turns is more tactics), while in chess there isn't.
Now here is the main reason I disagree that chess is the perfect example for intellectuals; ultimately blankflag is right (I will almost never say this). Chess, experience matters a lot but at the end of the day your just repeating the same game (black vs white) over and over again, looking at different outcomes. There are no do overs in real life and two armies are never employed identically across two battles.
The problem with chess and diplomacy is ultimately you've been in that when your tactics in diplomacy or chess are based mostly on experience (which every good chess player and dip player uses, past experience to help dictate their moves) is unrealistic. There are no other variables which is a problem.
A good strategist would be able to pick up a new variant and come up with a semi-decent strategy for each country, in light that in real life he would come up with multiple situations none of them identical. At the end of the day its a same game, the rules are the same, outcomes in each conflict are determined by the same factors, what changes in the map and therefore what the optimal strategies are.
Like in second time I played as Harold in a gunboat of the 1066 variant, I chose too rather then counter Haralds army in York, convoy my armies into Normandy. I banked on the fact that I could conquer Normandy before Harald could conquer England. This was a fog of war variant, so I relied on the fact that Harald would have no idea I had only 1 unit on the isle. That strategy had never been tried before, and I had no idea whether or not it would work, I just knew that if I fought Harald in the North, William would land armies in the South and either I would lose to William or fight a war on 2 fronts.
Like playing Known World 901, and in light of the Russian-Spanish-Denmark-French alliance that had all the map except for Asia, trying to find stalemate lines on your own, rather then rely on past experience to know them. Then, realizing no such line exists, you try to convince France (who is entering all holds at this point waiting for a 4-way draw) to stab Russia by convincing him you have a line that doesn't exist, and again, him believing you due to lack of experience.
Like in playing Africa for the first time, explaining to Nigeria why Morocco has the strongest starting position and you need to work together to stop him. (Morocco now has more solos then all the other countries combined on that set up, btw)
The advantage of playing variants is that you can't completely rely on experience, you have to be able to adapt your strategy, find the advantages and disadvantages of your country and conduct your opening diplomacy and moves based on what you think will work, not based on knowing it will work, which is what you see in Diplomacy.
This is why I enjoy variants, it adds a new variable that keeps us on our feet, since we have to analyze the game without fully knowing potential outcomes.