The letter to Benjamin Netanyahu, the prime minister, accuses Israeli forces of committing human rights abuses and war crimes "on a daily basis", including assassinations, torture, and collective punishment.
It also charges the army with damaging Israeli society and creating "a violent and militaristic masculine ideal where 'might is right'?". "It shapes the educational system, our workforce opportunities, while fostering racism, violence and ethnic, national and gender-based discrimination," the letter says.
While conscientious objectors, also known as refuseniks, are a long-standing phenomenon in Israel, this is the first mass refusal from pupils approaching draft-age in the past decade. All 18-year-olds are obliged to join the Israeli Defence Forces, although exemptions exist for Arab citizens and ultra-Orthodox Jews engaged in religious studies.
The movement to write to Mr Netanyahu gathered pace after would-be refuseniks contacted each other through social media. The prime minister has not responded, but the missive provoked condemnation from Yair Lapid, the Israeli finance minister and leader of the secular Yesh Atid party.
'Pampered, wealthy youngsters'
He called the teenagers "pampered, wealthy youngsters" on his Facebook page, and compared them with ultra-Orthodox Jews who refused to join the army on religious grounds.
Israeli Prime Minister Benjamin Netanyahu in his office in Jerusalem. Photo / AP
"To start with let's call this by its real name - this is not refusing, but dodging responsibility," wrote Mr Lapid, who initiated recent legislation curtailing army exemptions for religious Jews.
"Their secular evasion is not ideological. It is the pampering of wealthy youngsters who believe they deserve everything when others - your sons and mine - have to serve in the army instead of them."
The signatories responded that they hail from a variety of backgrounds, modest as well as affluent. and insisted they represent a cross-section of society.
'I am terrified of missiles'
Sitting in a cafe in Tel Aviv's southern suburbs, Daniel Elsohn, 17, refuted Mr Lapid's accusation that his refusal endangered other Israelis."I think the people who say this are trying to paint it as if going to the army protects," he said.
"I think going to the army is actually damaging my security as a citizen. I am terrified of missiles. I am terrified of explosions, of sirens, of all those things. They won't stop if we continue doing offensive acts in the name of defence."
Some signatories say they have faced abuse on the internet and from fellow pupils since the letter was publicised in the media, and that they expect their prospects to be hurt in a nation where army service is a stepping stone to the jobs market or further education.
Refusing to join the army does not automatically entail a jail sentence in Israel, where exemptions can be given to pacifists or on psychological grounds.
However, Omar Sa'ad, a Druze from northern Israel, is currently serving his fifth term in jail for refusing to serve, while another refusenik, Natan Blanc, was freed last June after 170 days.
Dafna Rothstein-Landman, 17, said she would risk jail to challenge the popular Israeli view of army service as a patriotic rite of passage. "The main purpose of the letter is to promote dialogue," she said. "We want to raise the question that is never asked - which is that serving in the military is seen as a matter of course."
