Tina Brown created a stir a few weeks ago when she wrote a column alleging that Hillary Clinton had been “invisible” in the position of secretary of state, declaring, “It’s time for Barack Obama to let Hillary Clinton take off her burqa.”

Unfair and inaccurate, the Obama camp and the Hillary camp charged. She’s constantly doing important work on the foreign-policy front. And we weren’t supposed to read anything into the fact that her husband handled the most sensitive and important diplomatic mission of this young presidency.

And now, this week, both the president and the secretary of state are on important, critical missions beyond our borders.

President Obama heads to Guadalajara, Mexico, to meet with the heads of state of Mexico and Canada for a summit that will focus heavily on the swine-flu virus and “an expected new wave of cases during North America’s upcoming flu season,” along with drug-cartel violence on the U.S.-Mexican border, mitigating Canadian anger over “buy American” provisions, and immigration.

Meanwhile, Hillary Clinton heads to Luanda.

That’s in Angola, where as part of her seven-nation trip through Africa, she “will emphasize Africa as a place of opportunity, built on an ethic of responsibility.”