Let's say 10 years in, you get deployed to <insert random combat theater where you have no internet access and limited phone access at best> and you have 30 properties at this point spread across the country.

I have met some people who invested out of state before they moved here and they did it before they moved, but with a partner (someone who was going to say there) so they had "boots on the ground" for help with managing the property.

Point #1 - foreigners can't own property - unless you're married to a nationalPoint #2 - you can own a condo - without being married to a nationalPoint #3 - you can Airbnb your condoPoint #4 - condos start around $38,000 upwards to $190K.I've toyed with the idea of offering a service to foreign investors as an American "with boots on the ground" to make sure their investment is properly setup. 

The only advice I have gotten thus far is have a team in place to be boots on ground when you need them to be.

And that is why I haven't been aggressive.I have endeavored to build my real estate portfolio using conventional financing with (mostly) 15 year mortgages at very competitive rates, and to only purchase properties that I thought would pay for themselves and generate free cash flow to boot, even with higher than anticipated vacancy rates and increased property taxes.

They can provide you "boots on the ground" knowledge as well as be a good source for referrals.

You need boots on the ground to view the property immediately.

If I were you, I would visit the apartments during the daytime and during the night time to get a realistic view of how they are ( be your own boots on the ground). 

Where I'm located the housing stock is predominantly quads and smaller... and its almost all converted SFH that are 100+ years old to boot (translated = rotted sewer lines, knob & tube electric, lead paint, asbestos siding & pipe wrap)... all the things that say OPPORTUNITY... and I've been missing it for over a year!

Reading "Fundamentals of Fluid Dynamics" doesn't make doing the problems simple, interviewing recent graduates about the struggles of boot camp doesn't make a 15 mile hike with 100lb easy, taking advice about how to fly in formation 100ft from another aircraft at night doesn't make it easier (or any less risky).