01French Foreign Legion
This one's so obvious that it had to come first.
The French Foreign Legion is the only branch of the French military that doesn’t require national citizenship to join -- in fact, joining as a citizen is a rarity. The Legion is legendary as a place to go to escape your past through military service specifically because it recruits non-citizens, who may join under an assumed identity. In fact, even though they no longer require use of assumed identities, the Legion's website stipulates that "[w]hatever your marital status is . . . you will be enlisted as a single man."
Of course, joining isn't exactly a vacation, even in the 21st century. Even after four months of basic training to become a legionnaire, recruits are forbidden a lot of luxuries that US servicemembers take for granted. Vacationing outside mainland France, buying a car, having a civilian bank account, getting married, and even wearing your own clothing off-duty are all denied to anyone who hasn't become a noncommissioned officer or served for five (sometimes seven) years.
On the other hand, it looks like some units in the Legion specialize in carrying axes and growing sweet beards -- so you can get a head start on that list of things to do after you leave the service.
02Australia & New Zealand
Yes, I'm aware that these are two different countries. But their recruitment programs are similar, they're next-door neighbors, and frankly, I like to economize on space.
Australia and New Zealand have both taken a novel approach to the prohibitive cost of training military personnel: They're outsourcing. Not all of their jobs, mind you, but just enough to fill key gaps. Both militaries have decided to start inviting veterans from the US military with at least three years' experience (and who were discharged less than three years ago) to bring their skills down under. In fact, each recruiting website features a detailed "wish list" of military occupations and ranks.
Transfers under the two countries' recruitment programs can apply for citizenship with as little as three months of service. As far as jumping ship goes, this one seems pretty treason-free: Australia and New Zealand are both US allies. (In fact, Oz routinely invites the US military over for training exercises.)
Also, making the switch can be pretty lucrative: Back in May 2012, Stars and Stripes pointed out that "an E-5, staff sergeant, with six years' service" in the US Air Force could boost his or her pay by more than $25,000 annually in Australia.
Even if you're not a citizen, men aged 18-23 and women 18-20 are eligible to serve in the Israeli Defense Force (IDF) through the Mahal program if they, a parent, or a grandparent are Jewish.
Given the political and military unrest of the Arab-Israeli conflict, that might sound like an extreme move to those of us without a Jewish heritage or a strong ideological link to the state of Israel. But the Mahal website prominently features Americans from Boston, New York, and other major cities sharing stories of their reasons for joining, as well as the personal benefits they gained from their time.
A mere 14-month enlistment is all that's required (or 18 months, if you need to go through the IDF's paid training to learn the Hebrew language) with basic training from 6 weeks to four and a half months depending on your assignment. The Mahal website also points out that IDF volunteers may become eligible for citizenship and other benefits such as "exemption from Israeli university tuition fees."
Yes, believe it or not, it looks like you're free to join the Red Army.
Russia's Ministry of Defence is curiously silent on their website but reports from regional news outlets like The Georgian Daily claim that foreigners have been eligible to join Russia's military since 2004.
Yes, recruits must speak fluent Russian. And yeah, it looks like the provision is really meant for ethnic Russians in the surrounding area, although the official law on the subject is apparently not so specific: One Moscow newspaper interpreted the law such that "theoretically . . . an Australian aborigine" would be welcome. But if you'd really like to serve Russia's Army, I'll let you find out for yourself if they'd welcome Americans into their ranks. (Then again, they didn't seem to object too strongly to Edward Snowden's presence.)
Foreign recruits could apply for Russian citizenship after three years, but there are a few downers: Foreign recruits are denied basic benefits normally offered to soldiers, such as vacation time. Then there's the fact that in Russia, there are nationalist groups that protest the flow of immigrants into the country. (Remind me again: Why can't the US and Russia seem to get along?)
Also, I hear they're doing away with those awesome fur hats. So there goes my only reason to join.
05Honorable Mention: North Korea
Just kidding. US citizens are expressly forbidden service in the Korean People's Army. (I'm sure the US wouldn't appreciate it, either.) And here I thought we had a good relationship.
Then again, you never know: Maybe the North Korean Navy would make an exception for someone with mad Photoshop skills.
Learn Which Foreign Militaries Accept US Citizens
It may seem unpatriotic of me to suggest jumping ship on the good ol' USA, but hear me out. As much as we should feel we owe a debt to our homeland for the freedoms and (relative) prosperity we enjoy, there may be other motivations, aside from treason, for joining a foreign military. And these days, budget cuts and sequestration mean that there may not always be enough enlistment contracts to keep up with the demands of every would-be soldier on American soil.
So whether for reasons of finance, religious affiliation, adventure, sightseeing, or just plain kicks and giggles, here are a few militaries abroad that accept -- and sometimes actively recruit -- US citizens to serve.