A special report in this week's Economist contains interesting data on the strength of the US military compared with other nations but it also warns that it is facing acute pressures.
The graphic above shows that the US accounts for approximately half of all global defence expenditure. Its share of defence expenditure is disproportionate to its share of world GDP and ten times greater than its share of world population.
The Economist article notes that the USA will struggle to undertake any other major military operation because of its commitments in the Middle East:
"These days American units get nothing like the recommended 2:1 ratio of dwell time to deployment. Some army brigades currently get barely a year to rest and re-train after serving 15 months, a ratio of 0.8:1. By this measure, American ground forces get a fifth as much rest as their British counterparts—and British commanders say that anything less than two years at home for each six-month deployment (a 4:1 ratio) could “break the army”."
Robert Gates, the Defence Secretary, is planning a 62,000 personnel increase in America's ground forces. This approximate 10% increase is only likely to be possible however with an increase in remuneration (for officers, in particular, where shortages are most pressing) and a reduction in standards:
"The quality of new recruits is starting to drop, with more in the lowest aptitude ranking, more high-school dropouts and more receiving waivers from disqualification (for example, for using drugs or having a criminal record). The age limit for recruitment has risen from 35 to 42, while fitness levels are lower. Some complain that training standards have also suffered, as the army adopts gentler means to get more recruits through boot camp."
Related link: UK defence spending at lowest level since 1930s