Koichi Hamada, a former professor of economics at Yale University who has been an architect of Mr. Abe’s revival policies, said the tax increase was never part of Abenomics. Rather, he said, it was a legacy from the previous administration, which passed a law mandating that it be put in effect this year. He said fiscal hawks within Mr. Abe’s own governing Liberal Democratic Party had urged the prime minister to let it take effect as scheduled to help tame Japan’s ballooning national debt, which has grown to the equivalent of more than two years of economic output and is already the largest in the developed world.

The real force behind the tax increase, he and others said, was the Ministry of Finance, the strongest of Japan’s powerful central ministries and an advocate of balanced budgets. As Japan’s deficits have spiraled upward during its long economic downturn, the ministry has pushed for increasing the national sales tax as the best way to raise new revenue.

Mr. Hamada and others said the ministry scared the Abe government into going through with the tax increase by arguing that any delay in the tax would make Japan look fiscally irresponsible and cause a stock market crash. Fiscal hawks like those at the ministry fear that a failure to address Japan’s national debt could lead to a crisis of confidence in which Japan can no longer sell its bonds.

But on Tuesday, Mr. Abe defied the fiscal hawks and postponed the second tax increase until 2017. Investors applauded his renewed focus on growth, sending stocks rebounding after the biggest one-day drop in six months on Monday. “The Ministry of Finance is a tough and powerful opponent, but Abe has the guts to fight back,” Mr. Hamada said.

Some analysts described the snap election as an attempt to curtail the ministry’s influence. By making the tax increase the election’s top issue, Mr. Abe is forcing the ministry’s supporters within his own party to fall in line behind him. “Calling the election is a calculated move by Abe to silence his opponents,” said Mr. Komine, the economist from Hosei University.

Mr. Hamada expressed optimism that the recession was just a temporary setback, and that the central bank’s decision late last month to pump even more cash into the economy would bring back growth. “The rocket has faltered, but it won’t crash,” he said. “Abenomics is still the right policy for Japan.”

Other experts are not so sanguine, pointing out that the tax increase was relatively small given the size of the economy. It was a sign of the underlying weakness of Abenomics that it caused such damage, they said.