The international accounting board was fundamentally reorganized more than a decade ago, thanks in no small part to the leadership of Arthur Levitt, who was then chairman of the S.E.C., and Lynn Turner, the commission’s chief accountant at the time. They insisted that members had to be chosen for technical expertise, said Stephen A. Zeff, an accounting professor at Rice University and author of a history of the international board.

In 2002, after the Enron and WorldCom scandals, Congress passed the Sarbanes-Oxley law, which provided financing for the American accounting standards board through fees levied on public companies. That was hailed as increasing the board’s independence by no longer forcing it to beg for contributions. But there is no similar financing mechanism for the international board.

The international board has not been immune to political pressures, a fact that alarms some investors. Most notably, the board suddenly agreed to let banks retroactively reclassify some assets to avoid having to take losses caused by plummeting market values during the financial crisis. That move came after members of the European Commission threatened to act against the board unless it caved.

Mr. Turner, the former S.E.C. official, is among the doubters. He concedes that the American accounting board has also succumbed to political pressures at times, but thinks the international situation is worse. And he argues that American markets have attracted investors in part because of better transparency provided by American accounting rules. “Why,” he asks, “would we want to give up that advantage?”

But he thinks the decision has effectively been made. When the S.E.C. agreed, in 2008 at the end of the term of Christopher Cox as chairman, to allow foreign companies to file reports using international rules, it probably set the country on a path that would be hard, if not impossible, for Ms. Schapiro to reverse, even if she wanted to do so. American multinationals say it is unfair that they cannot use the same rules that the S.E.C. allows overseas competitors to use, and that argument has substantial weight in Washington.

Thus it seems inevitable that those companies will be allowed to use international rules if they wish to do so. Equally, it seems to be politically perilous for the commission to force other American companies to do so, at least not anytime soon. So it seems all but certain that American companies will have a long — perhaps indefinitely long — time to switch, and that in the meantime, efforts will continue to align the two systems more closely.

When the S.E.C. acted to allow the use of the international standards without reconciling the numbers to American rules, it insisted that would apply only for companies that used the full international standards, as set by the international board, as opposed to the “carve out” ordered by Europe at the behest of French banks. But it may be that in the end there will also be an American set of international standards.