"In a recent conversation with a friend, we discussed how interconnected
global financial markets were (the conversation began with my assertion that the
European situation could cause a lot more pain the U.S. than consensus likely
believes).


Rather than make any bold statement of what this truly means (I am trying to digest it myself), I'll instead leave readers with two (conflicting) quotes:
Below are a few charts that outline just how interconnected things have
become.
The first chart shows the international investment positions of the U.S.
(the level of U.S. owned assets abroad and foreign assets owned within the
U.S.). I normalized the amounts by showing the level relative to the size of the
U.S. economy. As can be seen, the level of ownership both in and out of the U.S.
has spiked since the early 1970's, with foreign ownership of assets within the
U.S. increasing at a faster pace (U.S. owned assets abroad by almost 15% of GDP
or more than $2 trillion).

The next chart outlines what makes up that $2 trillion difference. While
U.S. investors own more in terms of foreign equity (direct investment and
stocks) than foreign investors own within the U.S., foreign investors are much
larger creditors within both the public (government) and private (corporate)
sectors.

Rather than make any bold statement of what this truly means (I am trying to digest it myself), I'll instead leave readers with two (conflicting) quotes:
“A creditor is worse than a slave-owner; for the master owns only your
person, but a creditor owns your dignity, and can command it.” -Victor
Hugo
“If you owe the bank $100 that’s your problem. If you owe the bank $100 million, that’s the bank’s problem.” -Jean Paul Getty
“If you owe the bank $100 that’s your problem. If you owe the bank $100 million, that’s the bank’s problem.” -Jean Paul Getty