The gloves have come off for the five cities competing to host the 2012 Olympic Games, but on Sunday at the SportAccord conference in Berlin, Germany, it was New York and London that made the bold moves needed to raise the bar in this battle as it heads into the final days of the campaign.

NYC2012 targeted the International Sports Federations directly – many of which were represented in Berlin by voting IOC members – with major marketing and sports development incentives that will help them gain a strong footing in the U.S. market. These offers embody the expected appeal of New York’s bid: broad exposure to a lucrative American audience.

The NYC2012 announcement that could sway meaningful votes would have won the day, except for the fact that London had an announcement of its own.

The British bid sweetened its proposal to International Federations, the National Olympic Committees, and Athletes with Olympic Charters with $20 million worth of subsidized perks and cash credits toward things like accommodation, transportation, and family benefits both before and during the Games. The kicker is a $50,000 credit to the National Olympic Committees, to be used to fund training camps in London before the Games, a cost of about $10 million to the bid. This package is broader-reaching than the program announced by Mayor Bloomberg and begs a further response from New York and the other 2012 bid cities.

It seems London has won a major victory in Berlin.

Immediately prior to the election for the 2010 Olympic Winter Games host city two years ago, the tiny ski resort town of Pyeongchang, South Korea, spread the word that it would provide free airfare for all athletes to travel to the Games. This was seen as a last-ditch attempt to save a bid that most had already written off. Minutes later, the Korean bid became an unlikely dark horse by decisively winning the first ballot. Vancouver narrowly won on the final vote, avoiding a shocking upset, but someone in London must have been taking careful notes.

Bid committees have always known that they need more than a good bid book to win. In the days before the Salt Lake City vote-buying scandal, the currencies included Super Bowl tickets, medical procedures, and Ivy League scholarships for IOC members’ personal use. Have bid marketers now discovered a new, more ethical currency – kickbacks to the organizations that make the Olympics possible?

Perhaps it wouldn’t be a bad thing. Incentives that result in funding the growth of amateur sports in developing countries and providing opportunities for more athletes to compete is congruent with Olympic principles and ideals. It is possible that the intensity of the bid competition will provide the political means for the IOC to take care of organizations that make the Games possible.

But the inherent danger of allowing such offers to remain unchecked might cause the bidding process to once again spin out of control – increasing the costs, risks, and exclusivity of hosting the Olympic Games.

Appropriately, IOC officials are questioning the “legality” of the offers from New York and London, sending the issue to the IOC Ethics Commission, which was set up after the scandal to ensure that bids abide by the strict rules. London officials claim that their offer was already included in their bid book and should be acceptable under IOC rules.

In the meantime, competing bids from Madrid, Moscow, and Paris are left in a precarious situation. Certainly each of these bids is capable of digging deeper and matching or beating the offers on the table, especially if it could lead to the spoils of an election victory. But if the Ethics Commission approves the plans presented at Berlin last weekend, the bid committees will have to decide whether to come up with an offer of their own or play a “clean” game and risk losing votes – and possibly the election.

You can imagine Salt Lake City bid leader Tom Welch facing such a dilemma in the early 1990s prior to losing a 1998 bid and then winning the 2002 bid, including his decisions that lead to charges of racketeering in 2000.

Paris has been the recognized front-runner in this race from the outset with a bid that has focused on experience and a strong technical plan, while keeping low-key on other issues. Bid leader Philippe Baudillon said that his team would abide by IOC rules and rely on the strong elements already contained in the plan, without duplicating competitors’ new incentive strategies.

For Paris, that could be a fateful decision.

Mr. Livingstone is producer of GamesBids.com.