Down here a screenshot of the interactive map of NATO capabilities.

From the map you can have access to information about NATO’s capabilities, such as air-, missile- and cyber-defence, special operations forces, precision munitions, maritime surveillance, etc…

From Wikipedia: NATO is a political and military organisation based on the North Atlantic Treaty which was signed on 4 April 1949. The organization constitutes a system of collective defence whereby its member states agree to mutual defense in response to an attack by any external party. NATO’s headquarters are in Brussels, Belgium, one of the 28 member states across North America and Europe, the newest of which, Albania and Croatia, joined in April 2009. An additional 22 countries participate in NATO’s Partnership for Peace program, with 15 other countries involved in institutionalized dialogue programmes. The combined military spending of all NATO members constitutes over 70% of the global total. Members’ defense spending is supposed to amount to 2% of GDP.

If you are interested in this topic, you can check this post about world fire-power: Full Ranked List of Global Firepower 2014.

Here is an interesting PROS and CONS of NATO from wiki.answers.com:

PROS: United we stand, divided we fall.

CONS: Everybody wants to be the boss.

What do you think of NATO as organization, does it facilitate peace or, instead, it is a US tool to gain more international power?