Why should international policy observers care about the election of a new pope? If you're a realist, the answer is not obvious. The Catholic Church, after all, has no divisions. But Dan Drezner offers a realist answer:

...the biggest reason the Pope matters from a power perspective is that, simply put, the Catholic Church is the most centralized religious organization in human history. -- hell, save the Communist Party, it might be the most centralized organization period.  With such a structure, it matters cruicially who heads it.  In contrast, the other major religions do not have anything close to the church bureaucracy or organizational resources. This is a banal point, but it's worth remembering in a century where the emphasis is on "networked" structures and the flattening of hierarchies and what-not. There are very good reasons for these kinds of organizational changes. If one cares about power, however, then centralization is still a crucial quality. 

Fine, but this stretches the definition of 'power' beyond its useful point. Stalin's famous question ('The pope? How many divisions has he got?') actually gets to the nub of the problem. No modern pope can force political change through military, economic or political power. What the pope has in spades is not power but influence and, most importantly, authority.

The accumulation of authority is a slow social process and is not dependent on power. Authority can in fact develop quite independently of any power. The Oxford English Dictionary, for example, is considered authoritative; it sets down rules about English spelling and usage, though no vote was ever taken, no approval ever granted and no bill ever passed to confer this authority. The OED has no power to enforce its rules, just recognition from individuals and institutions that its rules carry weight and ought to be respected.

In the modern state, authority and power commonly co-exist, with the government having a 'monopoly on the legitimate means of violence'. But power and authority are clearly not the same thing – the former, as Mao had it, comes from the barrel of a gun. Power is the ability to coerce, and we submit to power because we feel we have no choice. By contrast, people submit to authority because they feel it is legitimate. In modern politics, that authority often derives from democratic consent, but as the Catholic Church demonstrates, it doesn't have to.

Photo by Flickr user nathangibbs.