A little history: before Civ was Sid Meier's Civ, it was a board wargame from those hexes-in-a-box specialists, Avalon Hill. Civ the PC phenomenon has come a long way since then. Its breathless romp through time audaciously melds the history of ideas, politics and economics and is arguably more ambitious than any other game. But underpinning it all, the deep structure of Civ is an old bits-of-cardboard wargame.
That's why might is more than often right, as anyone who played the Romans in Civ IV, with their almighty - and some might say, imbalancing - Praetorian units, will know. It's why the first Civ IV expansion, Warlords, worked so well. By expanding and enhancing that wargaming core, it was on safe ground. And it's probably why Firaxis have designed Beyond the Sword the way it is.
Civ's militarist bent is clearly something that troubles Firaxis - Civ IV's religion and culture are obvious attempts to fashion new ways to play, rather than using new tech merely as an adjunct to an arms race. With BtS, they've sought to address this and other issues that could be seen to mar the Civ IV experience - such as the weakness of sea and coastal power, and the relative stasis of late play compared to the discoveries and expansion of early play.
How they've tried to do this is by tweaking some existing elements, like the tech tree, by adding new wonders and buildings, by totally revamping espionage, and by introducing a pseudo-religious corporate element. Oh, and by throwing in yet more military units - they just couldn't resist.
Of all the new features, it's the new wonders and buildings that do most to curb Civ IV's militarist tendencies. Two world wonders make religion far more powerful from the Medieval to Renaissance eras. The first, the Apostolic Palace, acts much like the United Nations wonder, allowing votes on various issues, including ending wars, stopping trade and re-assigning cities to other civs. It also opens up the possibility of a diplomatic victory much earlier than previously.
The second wonder is the Shwedagon Paya, which does for religious civics what the Pyramids do for governmental ones, namely make them all immediately available, which can give the civ in question a serious advantage if used wisely.
New national wonder the Moai Statues (those Easter Island heads) gives a production bonus to every water tile, giving watery civs a real boost. Similarly, new naval units and rules may at last give naval powers a chance.
Privateers are basically pirate ships that let you attack without being identified, while the Ship of the Line is a frigate beater. Modern vessels, the Attack Submarine, Missile Cruiser and Stealth Destroyer, perpetuate the sea battles; the new blockade rules allow all ships to seriously affect a rival civ's trade and cut off strategic resources.
Espionage has been completely overhauled and adds potential for the ancient spymaster. Whereas before, Spy units could only be built after learning Communism, now they can be up and running after developing Writing.
What's more, their missions don't spend your hard earned gold any more, instead drawing on your stock of espionage points. These accumulate every turn and are initially split equally among every civ you've encountered, but can be spread any way you like, enabling you to focus on a particular civ at a crucial time - before starting a war, say.
Like production, culture, gold and food, espionage is generated by specialist buildings such as Jails, Courthouses, the Palace and the new Security Bureau, letting you boost your spying if this black art appeals to you.