This is pretty darn specific. It must be tiny fraction of applicants. Hell, most Americans never leave the United States in their lifetime. The security concern about heavy debts or debts to unfriendly counterparties makes sense to me. But what is the security concern with "owning foreign property is unfriendly countries"? They can take it from you?
You have to remember that the DC area workforce has a lot of immigrants, people married to immigrants, and people who've done significant overseas stints. Plus there is a need for hiring linguists and cultural experts with fluency in unfriendly languages.
I know of TS clearance holders who have significant ties to Iran, Syria, Russia, and Afghanistan, but have renounced those citizenships and are loyal to the US. The clearance process works to figure out what levers those countries could still pull on them - foreign property and close family still there are the big ones.
"Are you an untrustworthy person?" Are you likely to take a bribe? Will you get mad at your boss and try to burn the place down, literally or metaphorically? Will you be careless in a way that brings about the same, with no malice?
"Are you as trustworthy as anyone else, but subject to inhuman pressure?" Anyone would be vulnerable to having a relative threatened; you probably don't want to hire someone who would be apathetic to having their parents or child threatened. If that relative is already in unfriendly hands, that's a huge risk.
In some ways, a $100k house in a (hostile) foreign country is no different than a $100k bribe; it's just stuff. If you ignore a threat to your property in a scheme to extort you, you are $100k poorer than if you give in, just like if you turn down a bribe. But humans are prone to loss aversion. Having $1 taken from you is far worse than receiving $1 is good, even ignoring any sentimental value of the property in question. Some people will still be able to ignore the threat, not allow themselves to be compromised, but a lot of people will find it hard.
For a job where security is a concern and you have thousands or millions of perfectly cromulent candidates, it's not crazy to winnow the pool first by discarding everyone who's untrustworthy or has extra levers that can be used against them. You still have thousands or millions of great candidates left.
Yes they can, which is why there are many many factors considered in granting and maintaining a clearance. None of them are simple black and white things. For foreign property, it is very different owning a small vacation house and owning a house where 3 generations of your spouse’s family live or owning a commercial property that provides a significant income to you. A foreign government putting each of those things at risk would have very different implications.
Only if you don't take 30 seconds to think about it.
Of course you can be compromised without owning foreign property. But foreign property is a vector by which you can be compromised.
Doesn't it make sense an intelligence agency would want to know all the possible vectors by which potential employees could be compromised? For each vector you'll have certain remediation steps, up to and including "don't hire this person."
sure, but it's way easier for the FBI to request the title and deed for things in the US and track their history than an apartment building in Panama, or a plantation in Indonesia.
they need to hire people who speak Arabic, or Chinese, or Hindi, and have ties they can utilize in those countries -- or at least understand well enough to build ties.
overseas money and property, esp. in unfriendly countries, rapidly becomes a concern in that sense. go double agent, have a friend overseas give you some sweet improvements to your house on the cheap, then sell it later for 4x than it's worth, and repeat.