The Iron Bank could be representing itself, being wealthy people of Braavos. Anti-slavery, anti-dragon, anti-piracy, anti-chaos (disruption to trade is bad) translates to supporting Jon on the Wall, Stannis as king... but why did Tycho extend credit to ransom Asha's men from Lady Glover? It seems odd the Iron Bank would do that not even knowing if Asha was alive at that point and extending the credit without a contract with Asha, especially since Asha is not a viable candidate for lordship of the Iron Islands, and Tycho had no reason to expect Theon was even alive. I suspect there is something more going on that Tycho Nestoris being nice, or gambling on a longshot to displace Euron.
Money is power, and surely the Iron Bank is a front for many powerful people to manipulate politics and finance in the world.
Doesn't that sound like our own dear Littlefinger? He's known to have made himself wealthly as Master of Coin for Westeros, and before that in various position rising up in the Vale, the Eyrie and Gulltown. His modus operandi is to sow chaos and profit from it. I could see Littlefinger putting up money to get the Iron Bank to back factions in Westeros, targetting the longshots like Stannis and Asha, selling the bad debt to wealthy merchants in the Free Cities and making a tidy profit when Stannis and Asha default on the debts. That's right, Littlefinger is a proto-Goldman Sachs.
The alternative is Littlefinger thinks Stannis actually might have a chance at winning the wars, so backing him is part of his scheme to get Sansa (and thus himself) back in power as Lady of Winterfell, and eventually of the Mountain and Vale, and Riverlands as well. After all, Stannis doesn't really have an heir that anyone would take seriously as a ruler. A weak, child queen if Stannis should die would need a regent to rule... someone like Littlefinger, perhaps?
ETA: I should have clarified, i don't believe the Iron Bank is a front for a single person or group like the faceless men. I believe anyone with money can approach them with a scheme and as long as their money is good, they can get the Iron Bank to front it.
Edited by SpaceChampion, 02 January 2012 - 10:40 AM.