The head of the Shin Bet on Sunday cautioned that releasing Palestinian prisoners held for decades would make it harder for Israel to secure itself, but said the resumption of peace talks would end up calming the West Bank.

The statement by Yoram Cohen came hours after the Cabinet debated whether to sign off on a deal to release 104 inmates in exchange for the resumption of peace talks. In the end the Cabinet okayed the deal, which will see numerous convicted murderers and terrorists — behind bars since before the Oslo Peace Accords of 1993 — freed.

According to Cohen, freeing certain security inmates will diminish Israel’s deterrence capabilities. He noted that a high percentage of released security prisoners have subsequently returned to terrorist activity, including some of those freed in October 2011 in exchange for kidnapped soldier Gilad Shalit.

However, Cohen said that entering peace discussions with the Palestinians would have “a certain calming effect in Judea and Samaria, particularly among activists who are affiliated with the Palestinian Authority.”

Talks between Israel and the Palestinians have been at a standstill since 2010, when they took place briefly at the tail end of an Israeli settlement freeze. Since then there have been sporadic outbursts of violence across the Palestinian areas, with some Israeli officials warning that a lack of a peace process will lead to a third intifada, or uprising.

Last week, Prime Minister Benjamin Netanyahu advised the Shin Bet of the pending decision to release long-time Palestinian prisoners in advance of the peace talks — a Palestinian demand before returning to the table — and asked the organization, in terms of security risk, to “rate” those expected to be freed.

Cohen provided his recommendations as to which prisoners should remain in prison, and who could be released without becoming a real threat to Israeli security. The suggestions are expected to be discussed in the near future by a ministerial subcommittee convened to deal specifically with the issue.

The prisoners are slated to be released in phases, depending on the success of talks, with the first group planned to be released as early as this week as negotiations kick off in Washington.

Gavriel Fiske contributed to this report.