Washington (CNN) Bernie Sanders, like the four other remaining presidential candidates, spoke of his views on Israel on Monday night.

But unlike his competitors, who flocked to Washington to lay out their positions to the American Israel Public Affairs Committee, Sanders declined to address the pro-Israel lobby in person.

Instead, he stuck to the campaign trail in the western U.S. and gave a foreign policy speech that took stances likely to grate on the ears of Israel advocates as well as to please them.

Though Sanders is the only Jewish candidate and one whose views were shaped in part by his time living on an Israeli kibbutz , he apparently saw little benefit in appearing at a forum that features few of his progressive constituents and might not be receptive to his positions on Israel.

Sanders advisers told CNN's Jeff Zeleny Monday that they made a decision that he would do better staying on the trail rallying voters ahead of Tuesday's contests.

Sanders has not spoke often of his heritage, his time in Israel or his views on the country now. Indeed, his speech Monday night in Salt Lake City represented some of his most extensive comments to date on the issue and they didn't feature many applause lines for AIPAC activists, who take a harder line on Israel than that articulated in his address.

"To my mind, as friends, we are obligated to speak the truth as we see it. This is what real friendship demands, especially in difficult times," Sanders said Monday, before calling for a renewal of the peace talks between Israelis and Palestinians.

But he then delivered a stern speech -- and one with rare details -- criticizing Israeli settlements, Prime Minister Benjamin Netanyahu and Israel's actions in the Gaza Strip.

"Peace will require strict adherence by both sides to the tenets of international humanitarian law. This includes Israeli ending disproportionate responses to being attacked, even though any attack on Israel is unacceptable," Sanders said according to his prepared remarks.

Elsewhere he said, "It is absurd for elements within the Netanyahu government to suggest that building more settlements in the West Bank is the appropriate response to the most recent violence."

Those aren't all positions pro-Israel advocates embrace, but some would have still have liked to have heard them from the candidate in person. And several Jewish leaders and members of the audience said they were chagrined that he didn't come.

"It's certainly disappointing, and I think if Hillary Clinton, Ted Cruz, Donald Trump and John Kasich can all show up, it's not clear why Bernie sanders couldn't fit it into his schedule," said Nathan Diament, executive director of the Orthodox Union's Advocacy Center.

"I think it's a statement. I think it's hurtful to the Israel-supporting community and the Jewish community. It's a very significant statement and hurtful," said Rabbi Philip Scheim, incoming president of the Rabbinical Assembly of the Conservative Jewish denomination.

While Sanders has expressed his support for Israel, Scheim said, "You have to demonstrate it more than state it."

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Scheim said Sanders' decision not to attend AIPAC was "probably" tied to not wanting to alienate segments of his progressive base of support. Scheim said Sanders' decision not to attend AIPAC was "probably" tied to not wanting to alienate segments of his progressive base of support.

And he acknowledged that even if the Vermont senator had attended, he probably would have trouble peeling away Jewish support from Clinton, who Scheim said has had "longstanding, strong connections" to the Jewish community.

An AIPAC spokesperson did not immediately respond to a request for comment Monday about Sanders speech and his decision to skip the event.

Some at the 18,000-strong gathering, though, understood why Sanders declined the invitation, given his politics.

"If he talked about his ideas, which most people here would consider too far left, you know he wouldn't win any supporters anyway. So he probably correctly recognized his time would be better spent campaigning out West," said Joseph Ennis, a software architect from Buffalo, New York, as he walked out of an afternoon session.

Ennis said it would have been "gutsy if he came and gave his true opinions based upon his record on the matter."

In addition to facing an uphill climb with the audience, Sanders might also have faced blowback among some of his supporters for attending.

Some 5,000 people signed a petition last week calling on Sanders not to participate in AIPAC, charging that the conference is featuring "Islamophobes."

Yet some on the left, such as Robert Naiman, policy director of Just Foreign Policy and president of the board of directors of the liberal site Truthout, urged Sanders to do as members of the Obama administration -- such as National Security Adviser Susan Rice -- had done before and be a "truth-teller" at AIPAC by publicly opposing Israeli settlements and other policies.

And many of Sanders' positions do fit in the mainstream of Democratic politics, even though they are out of step with AIPAC. That includes his support of President Barack Obama's Iran nuclear deal, which he cast in terms of military intervention in the Middle East and avoiding another Iraq war.

"The test of a great nation is not how many wars it can engage in, but how it can resolve international conflicts in a peaceful manner," Sanders said last August

His time in Israel, which he hasn't discussed much publicly, seems to have influenced his economic views at least as much as his geopolitical ones.

As a young liberal activist, he worked on a kibbutz, or collective community.

He and his campaign have been largely mum about the details, but he mentioned it in his speech Monday to establish his bona fides.

"Let me begin that I have a deep personal connection to Israel -- and I am fairly certain I am the only U.S. presidential candidate to have ever lived on a kibbutz for a while," Sanders said.

In an interview with The Associated Press in 1991, he went into more detail explaining not of how it informed his views of his Judaism but instead how it reinforced his belief in socialism and democracy.

"What I learned . . . is that you could have a community in which the people themselves actually owned the community," Sanders told the AP. "Seeing that type of relationship exist, and the fact that these units in the kibbutz were working well economically, made a strong impact on me."