The newspapers are talking about the new study saying only 1 in 4 youths is eligible to enlist in the military. Of course, the study doesn't break it down by race, but the information is readily available.

A 2007 Rand Corporation report prepared the Office of the Secretary of Defense, Military Enlistment of Hispanic Youth: Obstacles and Opportunities, has a lot of interesting information (although nothing, so far as I can tell, on whether devout Muslim majors are likely to shoot up Fort Hood):

Hispanics are underrepresented among military recruits. In 2007, Hispanics made up 17.0 percent of the general population (ages 18 to 40) but only 11.4 percent of Army enlistment contracts and 15 percent of Navy enlistment contracts. While the trend is upward (in 1994, 6.6 percent of Army contracts and 8.9 percent of Navy contracts were Hispanic), Hispanics are still underrepresented.

Social representation within the armed forces is an ongoing concern of policymakers. Indeed, each year, the Department of Defense is required by Congress to publish statistics on the social representation of the armed forces in terms of such characteristics as race, ethnicity, marital status, and age. An implicit goal is that diversity in the armed forces should approximate diversity in the general population. Furthermore, recruiting challenges in meeting enlistment goals mean that the services need to understand the factors affecting the supply of key demographic groups, including Hispanics. ...

Analysis of the NLSY data reveals that a relatively small percentage of youth, regardless of race or ethnicity, would qualify for military enlistment. Figures S.1 and S.2 show the cumulative effect of key enlistment standards in the areas of education (high school diploma or General Education Degree), aptitude (Armed Forces Qualification Test score, [AFQT]), weight, number of dependents, convictions, and drug-related offenses. Results are shown by race/ ethnicity for males and females, respectively, by service. Only 46 percent of white males, 32 percent of black males, and 35 percent of Hispanic males would be eligible to enlist in the Marine Corps, the service with the cumulatively least stringent enlistment standards. For females, the corresponding figures are even lower: 35 percent for white females, 22 percent for black females, and 24 percent for Hispanic females.

It looks like, judging from the graph, that for the hardest service to enlist in, the Air Force, only about 33% of young whites, 16% of blacks and 21% of Hispanics are good enough based on having a high school diploma, having an IQ of at least 92, not being fat, not having dependents, not having convictions, and not being on drugs. (Figure S.1)

We found that the major characteristics that disproportionately disqualify Hispanic youth are lack of a high school diploma, lower AFQT scores, and being overweight. ...

Though important, education is not the only major disqualifying characteristic of Hispanic youth. Hispanics who are high school graduates often fail to meet other enlistment standards. The services require that potential recruits take the AFQT. Based on their test results, potential recruits are placed in one of five categories (Category I is the highest). The services strongly prefer recruits whose score places them in Category IIIB or higher. The Department of Defense (DoD) restricts the annual accession of those in Category IV (the next-to-lowest category) to 4 percent of the total, and prohibits all recruiting from Category V (the lowest category).

Only 36 percent of young Hispanic high school graduates would score in AFQT Category IIIB or above, compared with 68 percent of white high school graduates. A key implication of this result is that increasing the high school graduation rate among Hispanic youth may not lead to comparable increases in enlistment eligibility. ...

Comparing Hispanics with other groups, we see that weight is another important disqualifying characteristic. Hispanics are considerably heavier than others: on average, Hispanic males weigh almost ten pounds more than white males. Seventy-nine to 91 percent of white males meet the service weight standards (weight standards vary by service), compared with only 71 to 88 percent of Hispanic males. Among females, the percentage who meet the weight standards is even lower; 63 to 82 percent of white females meet the standards, compared with only 49 to 71 percent of Hispanic females.

Our research shows that Hispanics have a lower prevalence of disqualifying major and minor conditions than whites. That is, except for weight, Hispanics tend to be healthier than whites. Research suggests that better-than-expected health in the Hispanic population may be due to the large proportion of immigrants; immigrants in general, regardless of ethnicity, tend to be healthier than the native-born U.S. population.

In general, Hispanics seem pretty healthy, other than weight-related problems like diabetes. Their infant mortality rate is quite low, for example.

However, Hispanics are more likely to be disqualified because of weight. On balance, taking all three health standards together (weight, major conditions, and minor conditions) Hispanic males are disqualified at about the same rate as whites. Hispanic females are substantially more likely to be overweight than white females, and more likely to be disqualified. Our analysis indicated that number of dependents is another disqualifying characteristic for Hispanics. Though not as important as weight, education, or AFQT, it is a significant factor, especially for females. Twenty percent of young Hispanics (ages 17 to 21) have children, compared with only 9 percent of whites. ...

Recruiting more intensively from the pool of qualified Hispanics will be challenging. Most likely, increasing representation among the Hispanic population will involve enlisting more marginal recruits. The services already have programs that seek to identify the best of these marginal recruits or to improve the AFQT, weight, or educational outcomes of those recruits.

Here's my adaptation of Table 6.1, which is based not on enlistment applicants but on a nationally representative sample, the National Longitudinal Study of Youth 1997, the successor to NLSY79 used in The Bell Curve:

	White	Black	Hispanic
Desirable: HS Grad & IQ >= 106	43%	11%	20%
Okay: HS Grad & IQ >92 but <>	30%	25%	27%
Ineligible: Dropout &/or IQ <= 92	28%	65%	53%

However, all else being equal, minorities are more likely to re-up in the military. So, the report goes on to discuss lowering enlistment standards for minorities. I didn't see any discussion, however, of whether it's better to, say, have a 120 IQ Explosive Ordinance Disposal tech who doesn't re-up after his initial term because he wants to get a degree in a mechanical engineering than one who doesn't have that opportunity.

By the way, according to Table 2.10, the maximum height for the Navy is 6'6" (low overhead on ships), so retired NBA star David Robinson, who entered the Naval Academy at 6'5" and graduated at 7'1" got special negative treatment by being ordered to serve two years as an officer. Anybody who wasn't a famous basketball player who grew to 7" over the limit would have been given an honorable discharge.

Lots more interesting stuff in this 224 page report that you won't read about in the newspapers.