U.S. Vice President Joe Biden, right, walking near St. Michael's Cathedral in Kiev, Ukraine, Tuesday, April. 22, 2014. Biden warned Russia on Tuesday that "it's time to stop talking and start acting" to reduce tension in Ukraine, offering a show of support for the besieged nation as an international agreement aimed at stemming its ongoing crisis appeared in doubt. (AP Photo/Sergei Chuzavkov)

It has been a really rotten few weeks for Vice President Biden. First came a trio of gaffes that earned him a Worst Week in Washington nod. Then, on Thursday, he suggested that being vice president is a "bitch."

None of these things, though, compare to something else Biden said in that very same speech Thursday.

Biden was forced to apologize over the weekend to leaders of both Turkey and the United Arab Emirates after suggesting in the speech at Harvard that these two countries and another ally — Saudi Arabia — were the United States' "biggest problem" in responding to the Syrian civil war.

“The Turks, who are great friends — I have a great relationship with (Turkish President Recep Tayyip) Erdogan, whom I spend a lot of time with — the Saudis, the Emiratis, etc. What were they doing? They were so determined to take down (Syrian President Bashar) Assad and essentially have a proxy Sunni-Shia war,” Biden said, according to AP.

Biden added: "They poured hundreds of millions of dollars and thousands of tons of weapons into anyone who would fight against Assad — except that the people who were being supplied were al-Nusra and al-Qaeda and the extremist elements of jihadis coming from other parts of the world.”

Biden also said Erdogan admitted to him that Turkey "let too many [foreign fighters] through" into neighboring Syria.

Needless to say, these are some pretty serious allegations. And they were met with some understandably hard feelings from countries who are supposed to be allies. Erdogan swore off his relationship with Biden and called for an apology, and Biden offered one Saturday. Then Biden apologized to the UAE on Sunday.

Turkish President Tayyip Erdogan reacts angrily after Vice President Biden says Ankara has supported extremist groups, including al-Qaeda. (Reuters)

This is all very inside baseball — so much so that most Americans probably won't tune in enough to process what just happened. But as Biden's many gaffes go, few are as damaging as this one. And in case anyone thought Biden has a real shot at becoming president in 2016 — something we've argued for a long time is folly — this should remind us why that almost definitely won't happen.

Biden's gaffes are a long-running subplot in Washington at this point. And most of them are along the lines of his "bitch" comment or using outdated and/or offensive terminology like "shylocks" and "the Orient."

All of it, though, paints a picture of a guy who can be pretty careless with his words. Sometimes that carelessness seeps into much more serious issues. And few things are as serious as international diplomacy.

To be clear, all of these things hurt Biden to some degree. He has created an image of himself as a sort of un-serious politician — a guy you'd like to have a beer with but wouldn't trust to run your country. And polling bears that out, with even many Democrats saying they don't think he would make a good president.

But while using offensive terms and even plagiarizing (which sank Biden's 1988 presidential campaign) are bad, alienating the countries the United States depends on for supporting its Middle East mission — something Turkey is still weighing — is quite another. And foreign policy is supposed to be Biden's strong suit.

Biden, who already had very little shot at becoming president in 2016, just showed precisely why that is — and caused the White House a massive headache in the process.