Former US ambassador Dan Shapiro, in a conference call on Monday organized by the Israel Project, said these visits are further signs of Trump’s seriousness “in trying to achieve the ultimate deal.”

According to Shapiro, Trump laid a good foundation for these efforts with positive interactions he has had with Prime Minister Benjamin Netanyahu, Palestinian Authority President Mahmoud Abbas, and the leaders of the Sunni Arab states whom he has met since his inauguration in January.

Trump, said Shapiro, has made clear that he has expectations of all sides. These expectations include Israel restraining settlement construction; the Palestinians halting payments to the families of terrorists and the terrorists themselves; and the Arab countries showing an openness to gestures of normalization toward Israel, such as economic ties and civil aviation links.

“It seems to me that these preliminary conversations led to the point where the time is coming for him and his administration to put forth their own ideas, perhaps a proposal of principles to guide negotiations on final status, and the steps each side can take to support that effort,” Shapiro said. The former envoy advised the administration to move quickly, saying that Trump is presently at his point of maximum leverage in the region, and that none of the parties — after those initial positive meetings — wants to say “no” to the US president. Trump had a successful visit last month in the Middle East, both in Saudi Arabia and Israel and the Palestinian Authority, and gained the trust of the leaders, Shapiro maintained. “He has established friendly relations, and each side wants to do more to deepen the positive relations with him.”

Shapiro said that Trump also made clear that “he has ‘asks’ of those leaders as well, and because of his known unpredictability, including his twitter feed, he is very difficult to say no to.” Concern about how he would respond on Twitter, if spruned, gives him additional leverage, Shapiro said. And it is into this breach that Kushner is now stepping, Kushner’s arrival and involvement in the process “raises the stakes for everyone,” Shapiro said, with the president’s son-in-law essentially daring each of the parties to say “no.”

“My guess is that they won’t,” he maintained. “Under the Kushner-Greenblatt leadership on behalf of the president, they put forward a set of proposed steps by each side to launch negotiations and support them with steps on the ground. My supposition is that no party will want to say ‘no.’ They may say, ‘ yes, but;’, or, ‘yes, with reservations,’ but I think they have a real opportunity if they move quickly to capitalize on the leverage the president has attained.”

But leverage has a tendency to dissipate over time, Shapiro said, as small disagreements with each party can gradually lower the cost of each subsequent disagreement, with the sides then finding it easier to say no. Trump’s domestic problems may also erode the leverage, another reason the administration may feel the impetus to act on this issue quickly.

“I think it is certainly possible for presidents to continued to conduct foreign affairs while dealing with domestic political troubles, and we have seen examples of that over many administrations in the past,” Shapiro said. “But it is true that if the investigation drags on for a long long period of time, and there begin to be questions raised about the future of the administration, that will contribute to a lessening of his leverage.”