In the past two weeks, President Obama has twice interrupted vacation and fundraising trips to take presidential planes to Washington for a brief period, only to turn around and fly back to his earlier location — once after just a few hours in the White House. Why the peripatetic travel schedule? Well, there was a wedding and a bachelor party involved — and an expensive mix of socializing, work, and vacation.

On Thursday, the White House announced Obama would travel to Westchester, N.Y., on Friday to attend a Democratic fundraiser. The president would then travel on to Newport, R.I., later in the day for another fundraiser. Then he would return to Westchester, where he would spend Friday night. On Saturday, Obama would attend the wedding of his personal chef and family friend Sam Kass and MSNBC's Alex Wagner at the tony Blue Hill at Stone Barns near Westchester. After the wedding, Obama would fly back to Washington.

On Friday, the White House abruptly announced a change in plans. Instead of overnighting in Westchester, Obama would fly from the second fundraiser in Newport back to Washington, where he would arrive at the White House a little after 11 p.m. Obama would fly back to Westchester 16 hours later, on Saturday afternoon, to attend the wedding.

Obama took what is known colloquially as "baby" Air Force One, comparable to a Boeing 757 commercial airliner. Figures from 2013 say "baby" Air Force One cost $42,918 per hour to operate, while the larger, Boeing 747 Air Force One cost $179,750 per hour to operate. However, newer reports indicate the big Air Force One now costs $228,288 an hour to operate, so it is likely that the (somewhat) smaller version costs significantly more than the 2013 figure, too.

So why make the schedule change, and incur extra, expensive time in the air, not to mention the even higher cost of all the support that goes into moving the president? Reporters wanted to know whether Obama's unplanned return to Washington had anything to do with conflicts in the Middle East and threats from the terrorist group ISIS.

"It is not specifically related to any sort of assessment or change in the terror threat that’s currently emanating from that region of the world," White House spokesman Josh Earnest said. "Merely, this is an opportunity for the president — when he saw his schedule — decided that he'd rather just make the late evening flight back here home to the White House. He can sleep in his own bed, do a little work tomorrow, spend some time with his family, and then travel back to New York tomorrow evening to attend a private event."

Reporters wanted to know if "a little work" involved meetings at the White House to deal with world problems. "I don't know at this point of any specific meetings," Earnest answered.

Critics speculated the real reason for Obama's change in schedule lay in his disastrous news conference late Thursday afternoon, in which he declared "We don't have a strategy yet" for dealing with the growing strength of ISIS in Syria. After his unforced and revealing gaffe, the theory went, Obama wanted to look like he was working hard on world problems.

But there might be a simpler explanation: Obama swung back to Washington to give his family and a few friends a ride to the wedding on Saturday afternoon. "The first family emerged from the residence at 4:37 p.m.," said a White House pool report. " FLOTUS [First Lady of the United States], Sasha and Malia were wearing black dresses and POTUS was wearing a black suit and tie. Marine One was wheels up at 4:40 p.m. They are traveling to Westchester County, NY, and returning early Sunday morning. Valerie Jarrett and Kristin Jones, a FLOTUS aide, are traveling with the family."

After Air Force One landed in the Westchester area, the family headed straight to Blue Hill at Stone Farms, arriving a little after 6:30 p.m. (To call the place expensive is an understatement; a prix fixe meal and wine tasting go for $336 per person, but of course the wedding location was the choice of the bride and groom.) According to pool reports, the Obamas stayed six and a half hours at the wedding, leaving at 1:05 a.m. Then it was back to "baby" Air Force One, which took off for Washington about 1:30 a.m. The Obamas arrived at the White House by helicopter a little before three. "The first family entered the residence at 2:55 a.m., still wearing their dressy attire," said the pool report. "Valerie Jarrett and Kristin Jones followed them into the residence."

Nearly two weeks earlier, Obama included a brief trip back to Washington in his 15-day vacation on Martha's Vineyard. The quick return was announced in advance, leading to much speculation about why the president would fly back to Washington simply to "attend meetings at the White House," as a press statement had put it. Did he have some big announcement to make? Whatever the reason, the president, traveling with daughter Malia on board the big Air Force One, left Massachusetts at 11:15 p.m. on Sunday August 17, after a full day of golf, a concert, and dining out, arriving at the White House at 12:40 a.m. Monday morning.

On Monday August 18, the president met with his national security team and, later, with Attorney General Eric Holder. As he had in Massachusetts, Obama made a brief statement to the press in the late afternoon about the situations in Iraq and Ferguson, Mo. But there was no big announcement, no big news — and no explanation of why he had returned to the White House from Martha's Vineyard.

Then, at 6:30 Monday evening, Obama's motorcade began rolling to the event that was likely the main, unannounced reason he returned to Washington: Sam Kass's bachelor party. "In a demonstration of Mr. Kass’s closeness to the Obamas," the New York Times reported ten days later, "Mr. Obama spent five hours in Mr. Kass’s Logan Circle apartment last week — in the middle of crises in Iraq, Ukraine and Ferguson, Mo. — ostensibly celebrating the chef’s last week as a bachelor." By Tuesday afternoon, Obama was again on Air Force One, heading back to Martha's Vineyard.

All in all, it's been an active, odd-hours time for the military and civilian workers who help move the president from one place to another: a quick trip from Westchester to Washington to pick up the Obama family to head back to Westchester for a wedding; another quick trip from Martha's Vineyard to Washington for a bachelor party, and then back to the Vineyard. It's what happens when a busy social schedule mixes with the complexities, and expense, of presidential travel.

Of course, no one should begrudge presidential travel; it's part of the job. And it is necessarily expensive for a President of the United States to move from place to place. But in recent days, the combination of Obama's frenetic travel, for less-than-urgent reasons, and his admitted lack of a strategy for dealing with pressing national security issues, has underscored the impression of a president who is constantly in motion, but doesn't know where he is going.