On Wednesday, President Obama spoke at a news conference in Martha's Vineyard about American journalist James Foley, whom Islamic State militants beheaded in a video. The president said such groups have "no place in the 21st century." (AP)

President Obama’s second shot at an August vacation — his continued effort to balance his presidential duties with a summertime break — looks to be as star-crossed as the first.

The shocking news of James Foley’s execution broke as Air Force One landed at Cape Cod Tuesday night for the second half of Obama’s trip to Martha’s Vineyard, following two days of White House meetings. The president offered his condolences to the American journalist’s family and angrily denounced Islamic State militants the following day. Then he went off for a round of golf — his seventh in 10 days.

It wasn’t the first time this month that Obama has made a quick pivot from grim news to the green. Last week, the president was confronted by rising unrest in Ferguson, Mo., and upheaval in Iraq. After delivering a solemn statement on both crises, he hit the golf course just four minutes after leaving the lectern.

If Wednesday’s remarks were the latest to throw the tough politics of presidential playtime into sharp relief, they’re unlikely to be the last: Obama still has roughly four days left before he heads back to Washington.

The president wasn’t the only world leader to see his vacation upended by world events this week. Three thousand miles away, British Prime Minister David Cameron was enjoying his own break in the seaside resort area of Cornwall — until news of the Foley situation broke.

On Monday, he defended his decision to go on holiday in language that echoed the White House’s defense of Obama’s Martha’s Vineyard break. “Wherever I am in the world I am always within a few feet of a BlackBerry, and an ability to manage things should they need to be managed,” he said.

But Cameron promised to return if the situation called for it. And on Wednesday, he announced that he had made that decision, calling it “increasingly likely” that a British citizen had beheaded Foley and saying he would chair meetings on the situation in Syria and Iraq. It remains unclear whether the prime minister will return to Cornwall or cancel the rest of his holiday.

Aside from public appearances, there’s another reason the prime minister returned to London: The mobile phone signal in Cornwall is problematic. Cameron has been known to drive to the top of a hill, desperately looking for cell phone reception so he can keep in touch with his colleagues in London and other world leaders. He’s become so disgruntled with the spotty service that he’s vowed to beef up the towers for better reception in the West Country.

It’s not just the technical amenities of a British prime minister’s holiday that lag behind his American counterpart’s. While writers, photographers and broadcasters travel everywhere with Obama, their movement is restricted to a press-pool arrangement. Cameron has to face roving paparazzi photographers.

And so both leaders may envy Russian President Vladimir Putin. Like Obama, Putin travels with a significant group of staff from the Kremlin, often 80 or more people. But members of the press are strictly forbidden.

Putin’s favorite summer vacation spot is Tuva, a wild territory on the border with Mongolia in southern Siberia.

It’s in Tuva that Putin has been snapped half-naked, hunting and riding — a somewhat different image from a golfing president or a sunbathing prime minister.

For entertainment, Putin enjoys local Tuvan throat singers. The singers are helicoptered in from local villages to perform for Putin and his companions in the evening.

But while the Russian leader may travel with an entourage, the president of the United States rolls far deeper. Obama essentially takes the White House with him wherever he goes — along with a press pool, a phalanx of staffers, a motorcade of more than 40 vehicles, and crisis-ready communication apparatus.

The president “has all the tools at his disposal no matter where he is, the same functional capabilities he has at his Oval Office desk,” said Steve Atkiss, who was deputy director of advance for President George W. Bush. When he goes anywhere, be it a day trip or a vacation, “the infrastructure follows him.”

As crisis after crisis has mounted this month, the White House has found itself once again defending the president’s decision to stick to his original vacation schedule — and his ability, beyond that of nearly any other world leader, to get the job done remotely.

“I think, as many have observed over the past few days, there’s never a perfect time for the president to take some time away with his family,” deputy press secretary Eric Schultz told reporters last week. “But I think we can also all agree that it’s valuable to recharge your batteries. And I just don’t think the American people begrudge their president for taking some downtime with his family.”

And so the president appears set to ride out the rest of the week — and whatever fresh chaos it may bring — at his favorite summer spot. Unlike Cameron, he may have a pressing logistical need to end his holiday early. Of course, given the way it’s gone so far, he may be wishing it were already over.

Katie Zezima contributed to this report.