Israel said Thursday that it agreed to trade Egyptian prisoners for a U.S.-Israeli citizen imprisoned in Cairo on unsubstantiated suspicions of spying to defuse a potential crisis between the two neighboring countries.

Israel's agreement to such a swap highlights how brittle relations have become between the two since the fall of Egypt's longtime leader Hosni Mubarak, and that many on both sides want to preserve them.

Israel released 25 jailed Egyptians, most of them smugglers, for the U.S.-born Ilan Grapel, who was arrested in Cairo in June and who previously served in the Israeli military.

The freed Egyptian prisoners passed into Sinai through a land crossing from Israel. TV broadcasts showed some of the Egyptian men kneeling to kiss the asphalt after crossing through a blue metal gate at the border.

At a news conference late Thursday in Jerusalem, Grapel said Egyptian authorities "made sure that I was fed well, respected me and made sure no one harmed me in any way."

Grapel said he was held on "trumped-up allegations." Israel's government, his family and friends insisted all along that Grapel was not a spy.

Many Israelis scoffed at the need for a deal to free a citizen arrested by a friendly nation on what were widely believed to be falsified charges.

Israel Hasson, an Israeli lawmaker dispatched to Israel to escort Grapel from Egypt, said the Israeli government agreed to free prisoners to ease recent tensions.

"This event could have developed into a crisis and we don't think either country needs that," Hasson told Israel Radio. "This was not a prisoner exchange. This was crisis prevention between Israel, the U.S. and Egypt."

In 1979, Israel and Egypt signed a U.S.-brokered peace treaty, the first between Israel and an Arab state. Relations have always been cool, but Mubarak carefully upheld the accord.

Egypt's new military leaders have vowed to do so as well, but they have taken a tougher stance on Israel and grown closer to its enemy, the Hamas militant group that rules Gaza — a tiny coastal Palestinian territory that borders both countries.

Egypt's improved ties with Hamas appear to have helped secure a long-elusive prisoner swap last week, in which Israel agreed to trade more than 1,000 Palestinian prisoners for a single Israeli soldier, Sgt. Gilad Schalit, who was captured and held by Hamas in Gaza for more than five years.

But Grapel is no Schalit.

He was volunteering at a legal aid group in Cairo when he was arrested in early June on suspicion of spying for Israel during the grass roots revolt that overthrew Mubarak. He was never charged.

Grapel made no secret of his Israeli background, entered Egypt under his real name and his Facebook page had photos of him in an Israeli military uniform. Such openness about his identity suggested he was not a spy, and even in Egypt, where hostility toward Israel runs high, the arrest was widely ridiculed.

Grapel was born in the U.S. and moved to Israel, where his grandparents lived, as a young man. He did his compulsory military service in Israel during its 2006 war with Lebanese Hezbollah guerrillas and was wounded in the fighting. He later returned to the U.S. to study. After his legal internship in Cairo, he planned to return to Emory University in Atlanta for his final year of law school.

A smiling Grapel looked fit after his one-hour flight from Cairo. On the tarmac at Ben-Gurion International Airport outside Tel Aviv, Grapel, 27, embraced his tearful mother, Irene, who traveled to Israel from her home in Queens, N.Y.

He was also greeted by U.S. Rep. Gary Ackerman — a Democratic congressman from New York for whom Grapel interned in 2002 — and U.S. Ambassador to Israel Dan Shapiro. The entourage then traveled to Jerusalem to meet with Prime Minister Benjamin Netanyahu, who warmly shook Grapel's hand.

Grapel plans to remain in Israel for at least two days to meet with Israeli and American officials before returning to the U.S.

The U.S. Embassy in Cairo took the lead in Grapel's case because he entered Egypt with his U.S. passport, and Ackerman lobbied for his release.

In Washington, State Department spokeswoman Victoria Nuland said the U.S. "worked hard to bring (Grapel) home." She added, "The Egyptian-Israeli Peace Treaty is a vital element of regional peace and stability, and we strongly support both countries' sustained commitment to its provisions."