During his spring visit to the United States, Japan’s Prime Minister Shinzo Abe stood in the well of the House of Representatives and promised: “I will pass national security legislation by the end of summer.”

He was referring to a new law and amendments to nearly a dozen other laws relating to the deployment of the Self-Defense Forces (SDF). They would provide legislative mussel to the Abe cabinet’s decision one year ago to “reinterpret” the pacifistic constitution to permit collective defense.

At the time it seemed, especially to Washington which welcomed the return of the conservative Liberal Democratic Party (LDP) and Abe back to power, that fulfilling this promise would present few difficulties. After all, the LDP and its Komeito coalition partner hold commanding majorities in both houses of parliament.

Washington was so sure of Abe’s legislative clout that it agreed to publish new joint guidelines for joint US-Japan cooperation in defense matters even before parliament voted on the amendments that are needed to implement the agreement.

Now there are signs that parliamentary approval of the measures this summer isn’t going to be a cake walk. Public opinion polls show growing numbers of Japanese opposing the new security laws, while the cabinet’s approval ratings, now about 40 percent, are beginning to fall.

In one sign that the government is getting worried, the prime minister extended the current session of the Diet, which was due to adjourn this month for the summer holidays, until the end of September. It is the longest extension since the end of World War II.

The tide began to turn in early May when three constitutional scholars testified before a parliamentary committee that the proposed laws were unconstitutional. Opposition took on added force as one of the three had been appointed by the government. The media played up their views.

Then the government was embarrassed when some of the younger members held a “study session” in which they debated ways to punish the press over their editorials and coverage of the security bills and other defense-related measures. One of those asked to speak was novelist Naoki Hyakuta, an extreme reactionary who said some of the unfriendly newspapers in Okinawa “must be destroyed.”

Hayakuta is not a member of parliament but served on the governing board of NHK, Japan’s state broadcaster, as an Abe appointee. The prime minister, who did not attend the meeting was forced to formally apologize, “It was extremely inappropriate,” Abe said referring to the language used by those attending.

One more fumble like that could be fatal to the bills, said party secretary general Sadakazu Tanigake.

What’s emerging is a potentially fatal combination of a difficult-to-explain security need and a prime minister who is not trusted, either at home or abroad, on matters of history. He harbors revisionist views on Japan’s role in World War II, which makes it seem to some that he is eager to launch 1930s-type adventures.

Never mind that the actual legislation is fairly modest in practice. Mostly it is designed to enable closer cooperation with existing allies like the United States and potential allies like the Philippines in situations that threaten the Japan’s security.

The situation is beginning to look eerily like the 1960 when the then Prime Minister Nobusuke Kishi, who happens to be Abe’s grandfather and in many respects his role model, rammed through parliament the security treaty with the US in the face of massive demonstrations that forced President Dwight Eisenhower to cancel a planned trip to Japan.

Things have not yet reached that point, though there was recent a demonstration of about 45,000 people in downtown Tokyo opposing the new laws, and there may be more, especially next month when Japan will mark the 70th anniversary of the end of the war.

It is not certain whether Abe will be forced to copy the strong-arm tactics that his grandfather used to ram the treaty through the Diet in 1960 but that may change during the long hot summer. Abe’s majority looks impressive on paper, but numbers can deceive. Japanese take offense at high-handed parliamentary tactics and may punish the party in the next election for them.

There are some signs that Abe himself isn’t so sure that he has the votes to pass the laws. One is the unusually long extension of the current parliament through the summer. It may show he is worried about whether the bills can pass the upper house, and he wants time for the lower house to be able to override an upper house defeat.

Another sign was a curious recent meeting with Toru Hashimoto, one of the founders of the Japan Innovation Party, which has the third-largest bloc of votes in both houses. It suggested that Abe may be fishing for insurance votes in that party (which has proposed its own versions of the bills.)

So far, there are no other indications of a revolt against the government by LDP back benchers. Its coalition partner, Komeito, has also been quiet. Though Komeito is more pacifist than its partner, it endorsed the new bills after a series of consultations and negotiations.

But bets could be off if the government’s public approval ratings continue to fall during the summer. Long time Japan watcher, Takeo Toshikawa, writing in The Oriental Economist, says the cabinet’s approval ratings may fall five percentage points each time the bills are passed through a committee or plenary session.

If approval continues to fall steadily many of the younger LDP members, fearing for their seats, may begin to bolt. If that happens, and especially if the government has to pull the bills, Abe might find opposition to his reelection as party president in September, a prerequisite for being premier, where he previously was considered a shoo-in. In that case Abe may have to take another lead from his distinguished grandfather, who was forced to resign as prime minister after the 1960 security treaty debacle.