As U.S. investors — everyone from Wall Street to Main Street to Washington — sit transfixed at the machinations of the Trump administration, it would be wise to remember there are other events taking place in the world that merit our attention.

There has been, of late, a brisk “flight to quality” trade going on in U.S. Treasury bonds and in gold, reflecting not only concern about certain Trump administration policies but also about events in the world at large.

With little fanfare, and scant mention, Greek bond yields have been soaring of late, as Athens and the International Monetary Fund argue about the terms of the most recent Greek bailout and whether or not Greece is adhering to the agreement.

In addition, Greece faces a large debt payment upcoming, which if not met, could trigger Grexit 3.0!

Speaking of exits, with the French presidential election looming on the horizon, there are mounting concerns that France’s alt-right candidate, Marine Le Pen, may win the election. She is running on a platform that includes pulling France out of the European Union, showing a Trumpian distaste for multilateral agreements and globalization.

French bond yields are rising, as well, as investors are taking precautions against an event that would, no doubt, weaken France’s economic and financial standing on the continent.

Rather ironically, the entire notion of the European Union, which has its roots in the 1957 Treaty of Rome, was designed to halt German aggression by linking, specifically, Germany and France’s economic future together.

World leaders who planned the post-war world believed that if the core of Europe — France, Germany and the surrounding countries — did well together, Germany would be unlikely, or certainly less likely, to launch a third and more destructive global war.

Farther away, China is spending quite a bit of money in an effort to support its currency, the yuan. The defense of the Chinese currency — through capital controls, price fixing and other measures — shows just how weak China’s economy is internally, despite what Chinese officials proclaim to the external world.

The Wall Street Journal has a telling pictorial essay on the shipbuilding “rust belt” in China, illustrating the massive overcapacity in an industry on which China had based a large part of its growth.

This also flies in the face of President Trump’s claims that China is purposely devaluing its currency to sell more exports abroad. To the contrary, China, which hopes to make the yuan one of the world’s quasi-reserve currencies, has been propping it up so that it can be used in a basket of international currencies that make up part of the IMF’s proxy currency, the so-called “Special Drawing Rights,” or SDR.

So while we have much to consider here at home, from the court battle of the immigration and refugee ban; the apparent waning ability of Congress to repeal and replace the Affordable Care Act; the prospects for tax reform; deregulation; infrastructure spending and other domestically focused measures, there are some emerging developments outside the U.S. that could rattle markets in the near future.

U.S. stock indices have not had a move as large as 1 percent since the election. If any one of these external events, which are not currently being closely monitored, except by the professional investing class, individual investors may be taken by surprise, if the market suddenly swoons.

Forewarned is forearmed, as they say.

This is a forewarning!

Commentary by Ron Insana, a CNBC and MSNBC contributor and the author of four books on Wall Street. Follow him on Twitter @rinsana.

For more insight from CNBC contributors, follow @CNBCopinion on Twitter.