There are a number of different ways to determine which countries have the highest military expenditures. When looking just at actual dollars spent, the United States spends far more than any other nation. The 2012 US Department of Defense budget includes $553 billion US Dollars (USD) as a base, and, when combined with recent supplemental war spending, the total is estimated at over $670 billion USD; that number has dropped from 2011, when it topped $700 billion USD. Coming in a distant second is China, with an estimated $119 billion USD. With combined world military spending at about $1,630 billion USD in 2010, recent US military spending has made up more than 40% of that total.

The People's Republic of China is often near the top of the list of countries with the highest military expenditures.

Military expenditures can be looked at in other ways, however. Looking at expenditures as a proportion of a country's gross domestic product (GDP) can provide insight into how that spending compares to the country's total economy. When provided by this method, Oman is at the top of the list, and the US falls to 24th.

Singapore has one of the 20 highest military expenditures in the world.

Here are the top 25 countries in terms military spending as a percentage of GDP according to the CIA World Factbook. The figures are taken from the most recent year for which information is available, 2005 and 2006 for most nations.