Last night the Post's Rajiv Chandrasekaran noted U.S. Marines still train on bayonets in boot camp and Marines still are issued bayonets as standard equipment, though the Army discontinued bayonet training at its basic training facilities in 2010.
This 2009 article from the Washington Post Magazine followed a platoon of Marines battling insurgents in Now Zad, Afghanistan. The first words of the article: "Fix bayonets."
Not long after giving that order, 1st Lt. Arthur Karell was hunched in a dirt trench crowded with Marines. The hushed darkness bristled with eight-inch blades fitted beneath the barrels of dozens of M-16 assault rifles.
You fix bayonets when you expect to need the aggressive combat mind-set that's produced by the primal sight of massed blades. You fix them when you expect to search hidden places. You fix them when you expect the fight could push you within arm's reach of your enemy -- gutting distance. In modern warfare, that's extraordinarily rare.
Slate's Explainer has more on the modern use of bayonets. While incredibly rare, there have been a couple notable bayonet charges in the past decade.
Of course, President Obama never said that bayonets were nonexistent -- only that they are far less prevalent than they used to be.