Mark Krikorian (of the Center for Immigration Studies) has an interesting editorial in NRO about non-citizen soldiers:

Over the past month, the journalistic hive has cranked out a tidal wave of stories on immigrants in the military, orchestrated in part by the high-immigration advocacy groups. The objective was clear from a Wall Street Journal story earlier this month: "the prominence of immigrants such as Sgt. Gomez among the armed forces is helping to temper the emotional debate over immigration to the U.S. in the wake of the attacks on the Pentagon and World Trade Center." In other words, the media is lecturing America's ignorant masses that not all immigrants want to kill us.

Want another example? See the recent pro-illegal-immigration SF Chronical editorial. Krikorian continues:

...Not to put too fine a point on it, we should go to any length to avoid developing a kind of mercenary army, made up of foreigners loyal to their units and commanders but not to the Republic. It didn't work out well for the Romans...

For more on the general illegal immigration issue, see Krikorian's recent testimony before the House of Representatives: "Securing the Homeland Through
Immigration Law Enforcement"