It's exactly like a foreign investment in some ways it isn't in others. It's an exchange of sorts but is not free-market capitalism at play but rather clumsy foreign policy (the example you gave was not done for money but to fight a mutual enemy).
In this case it's foreign investment in a free market. I insist so strongly on calling the fear against certain foreign investment xenophobic because capitalism renders corporations rather unpatriotic in nature yet individuals still see even the most benign foreign investment as invasive on occasion.
They see a suspicious-looking nationalistic foreigner where cold hard and unpatriotic greed is quietly going about making money. Remember the 80's and 90's when Japanese investment in the US was much more substantial
than this and all sorts of ill was supposed to befall the US as old foes bought up land and iconic American corporations? Where the heck did any
of those fears show up in the real world? Read this article
from 1990 and share a laugh with me would you at unfounded paranoia that was also tied to national security.
Thing is, economic contagion brings a desire for political stability and increases social interaction between peoples. In many cases it brings friction of culture clashes but in the long run it generates more empathy.
And when push comes to shove there is a powerful force called greed that helps keep people friendly because in the modern economy rocking the boat usually makes a lot of people lose money if there is a decent amount of trade between the nations.
There is a (false) saying that no two nations with McDonald's have gone to war. It's not quite true but very close. There are a god-awful number of reasons why but I believe that the biggest one is that developed economies don't tend to want to fight each other.
Dubai and the UAE have been moving away from an oil-based economy to a tourism and trade based economy. Their economic success relative to their Arab counterparts shares a relationship to the fact that their foreign policies tend to be much more western-friendly in my opinion. And their continued economic growth is something I see as a key to reducing the fundamentalism that really does cause wars.
Being quite the religious fundamentalists, they aren't quite there yet. However with economic development, education and secularism grows and Americans should cheer Arab economic development.
With that position, I think their choice to diversify their investments into this particular holding is a damned good idea.