On June 21, David Cameron stood in front of the prime minister's residence at No. 10 Downing Street and made a last-ditch plea. "Brits don't quit," he said, urging voters, particularly older ones, to side with him and elect to remain in the European Union. "We get involved. We take a lead. We make a difference, we get things done."

Just three days later, on that famed stoop, he would do exactly that: Quit. Hours after British voters shocked the world by voting to leave the E.U., the very man who said he would remain in the job if he lost, the very man who called for the referendum in the first place -- a reckless and needless political tactic -- resigned, right there, on the spot.

It was a stunning moment that may have ultimately been inevitable for the prime minister, but did nothing to spur confidence in a country that has seen a gaping void open in its leadership. The world may be reeling from 'Brexit's' grim economic fallout -- the warnings of recession, the 30-year drop in the value of the pound, the global stock market declines -- but the leadership fallout from Britain's stunning vote is just as, if not more, ominous.

A new prime minister won't be named until September. Both major political parties are in disarray, with one locked in a divisive leadership battle and the other ensnared in an attempted coup. In the immediate aftermath of their victory, even some of Brexit's key supporters were either walking back promises or went largely missing from public view.

Nicola Sturgeon, the politician who has said another Scottish independence referendum is possible -- Scotland voted overwhelmingly to remain in the E.U. -- put it this way in an interview with Sky News Sunday: "At a time when the whole United Kingdom needs leadership probably more than it’s needed leadership in any part of the postwar period, you have got the Conservative Party and the Labour Party completely abdicating responsibility. They are letting down people across England, across the entire U.K., and I look on in utter horror.”

Cameron's renunciation of responsibility began much earlier, when he decided, back in 2013, that a referendum on the complex question of Britain's membership in the E.U. was something the average British citizen should settle. A gamble seen as a low-risk way to quiet the anti-European Union wing of his party in the run-up to Cameron's re-election in 2015, it turned into a high-risk political move that shifted a decision best left to the experts in positions of leadership into the hands of the masses. Cameron put short-term gain before long-term wisdom -- a leadership error in any case.

A "Faustian bargain," presidential historian Doris Kearns Goodwin called it on "Meet the Press" Sunday, one that would have iconic British Prime Minister Winston Churchill "dying in his grave right now. He did it to himself. The leaders of both parties were not able to reach the people, which shows that something's wrong with the leadership. ... They didn't argue passionately enough, they didn't emotionally connect to the people who felt that something was wrong."

With the defeat -- a blow to Cameron's authority -- holding on to his party's leadership may have been impossible, even inadvisable, given his role in creating the referendum. But we will never know, as he quickly reversed his pledge to stay on and see it through, however narrow the majority and however many regrets quickly surfaced over the vote. There was little attempt in his resignation speech to staunchly defend Britain's membership in the E.U. other than a softly worded "leaving Europe was not the path I recommended." And speaking of Churchill, there was none of the "never, never -- in nothing, great or small, large or petty -- never give in" grit.

Cameron's call for "fresh leadership" in his resignation may have been an attempt to move forward, but the vacuum it created could very well hold Britain back. His party hardly seems to be lining up in lock-step, with the two most likely contenders for the job highlighting the divide among Conservatives. First there is former London Mayor Boris Johnson, who became the face of the "leave" campaign and gets the oddsmakers' top nod -- yet reports said there are forces within the party trying to keep Johnson from landing the top spot. Meanwhile, British Home Secretary Theresa May, who favored that Britain remain, leads a new poll of Conservative voters.

Yet if Johnson is seen as the most likely contender to replace Cameron, he did little over the weekend to reassure voters of his leadership role, even prompting a #WhereIsBoris hashtag on Twitter. (A similar one greeted George Osborne, Britain's Chancellor of the Exchequer, before he made a statement of his own Monday morning.) Johnson was seen playing in a charity cricket match but otherwise kept a low profile before late Sunday, when he published an op-ed in the Daily Telegraph. He has not faced the media for detailed questions.

Amid that turmoil, perhaps there is strong, steady leadership in another party to take the reins? Hardly. Simmering rebellion against Labour Party leader Jeremy Corbyn boiled over into even greater disarray since the vote, as a cascade of members from his shadow cabinet resigned in open revolt. Corbyn remained defiant as he failed a no-confidence vote Tuesday.

Surely those who supported the idea of "leave" are filling the void with confident leadership? Try again. United Kingdom Independence Party leader Nigel Farage backed away from a pledge that 350 million pounds would go to Britain's National Health Service instead of the E.U., saying it was a "mistake," then taunted members of the European Parliament Tuesday. Liam Fox, a former cabinet minister who supported the exit, told the BBC "a lot of things were said in advance of this referendum that we might want to think  about again." Johnson's op-ed in the Daily Telegraph, the Post reported, seemed to "walk back promises that a non-E.U. Britain would be able to dramatically limit immigration."

Well then. Where does that leave British voters -- or for that matter, the rest of the world? Facing the potential for economic recession, corporate defections, even the potential breakup of their own country -- and so much more -- how can Britain move forward when such a leadership vacuum exists? How does one keep calm and carry on when leadership is in such turmoil?

It's remarkable that the country once led by Churchill and Margaret Thatcher, by Clement Attlee and David Lloyd George, by "conviction politicians" who stared down their own historic moments is facing such a leadership crisis now. Certainly, some level of jockeying and anxiety is natural at a time of such historic change. But to see such a vacuum in every direction in Britain -- from both major political parties, and from even those who backed the exit -- is wholly disconcerting. Brexit's economic and diplomatic challenges cannot be resolved until someone steps up to fill a void that's growing wider by the day.

For now, the "statesmen" Churchill said were needed to make the "world-saving decisions," the ones "where the balance quivers, and the proportions are veiled in mist" seem nowhere to be found.

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