Amos Gilad, head of the Defense Ministry's Diplomatic-Security Bureau, told this week's Herzliya Conference that Israel should try for a peace treaty with Syria within "the parameters at which we have arrived, but with vital additions which constitute red lines." Gilad believes that Israel needs to make peace with Syria because the two countries are on a collision course. Gilad shuttles between here and Cairo meeting with Egyptian Intelligence Chief Gen. Omar Suleiman about a Gaza cease-fire, freedom for Gilad Schalit and such sensitive issues as smuggling underneath the Philadelphi Corridor. When he speaks, people listen. Syria has the capacity to rain deadly missiles on Tel Aviv, Gilad said. A peace treaty de-linking Damascus from Teheran would therefore reduce Syrian support for Hamas and Hizbullah and improve Israeli security dramatically. But if a treaty isn't signed, Bashar Assad may provoke a war. The ensuing Israeli retaliation could bring down his Alawite government, to be replaced by a less cuddly, radical Sunni regime. This summation of the obvious notwithstanding, Gilad's fleeting reference to "red lines" deserves elucidation. Demarking such lines - the point beyond which Israeli policymakers cannot safely go - is essential, both in order to build a domestic consensus and to help Israel articulate a coherent position in the international arena. Red lines can translate into tangible ones. An Israeli-Syrian peace agreement could place our border along (1) the 1923 boundary; (2) the 1949 Armistice Line; or (3) the June 4, 1967 line. Presumably, Israel balks at handing over the former demilitarized zone, or pulling back to the 1949 demarcation. Other Israeli red lines would surely include ironclad guarantees for a demilitarized Golan and the unobstructed flow of water. Talking about Israel's safety, what guarantee do we have that once a Syria-Israel peace treaty was in place - and the Golan abandoned - Damascus-Teheran relations wouldn't revert to normal; that Syria wouldn't continue to give Hamas leaders safe haven; and that it wouldn't go on funneling Hizbullah weapons? Should these doubts prompt red lines? When Israeli strategists like Gilad speak in shorthand, assuming that "everyone" knows Israel's sticking points, they do the country no favors. They need to do a better job of defining them. Far better if they helped build a consensus about those pesky red lines. Should Israel insist, for instance, that Assad recognize Israel as a Jewish state? That he visit Jerusalem? Assad is holding out a cold peace. What about holding out for a "warm" one? RED LINES also identify minimum needs. Israelis generally assume that statehood is the Palestinians' red line. But what if their true red line is the one enunciated in December 2000 by Saeb Erekat: "The whole peace process hinges on Israel's willingness to withdraw to the borders of June 4, 1967â€¦ and come to terms with the refugees' right to returnâ€¦" Mahmoud Abbas today is still demanding: a total pullback to the 1949 Armistice Lines; the redivision of Jerusalem, and the "return" of millions of refugees, and their descendants, to Israel proper. How are these red lines, representing the most "moderate" Palestinian position, to be reconciled with those of Israel's mainstream? It's hard to fathom. Putting aside the issue of Hamas's control of Gaza, most Israelis would anyway insist on "1967-plus" - retaining strategic settlement blocs along the Green Line; a demilitarized Palestine, and control of the airspace and electromagnetic environment over Judea and Samaria. An IDF presence might long be necessary in the Jordan Valley to protect against threats from the east. Israeli negotiators thus need to determine whether Palestinian red lines are indelible. It may be that they aren't. Just four decades ago, the Arabs declared: "No peace, no negotiation, no recognition"; today Israel has formal peace treaties with Egypt and Jordan, and is talking to the Palestinians. ISRAEL'S NEXT coalition government needs to put defining this country's red lines high on its agenda. Our negotiators can then take those parameters, reflecting a national consensus, to the negotiating table. Binyamin Netanyahu may be best suited to help us identify our red lines at home; Tzipi Livni might be more credible at marketing them abroad. Crystallizing red lines is not about throwing down the gauntlet, it's about knowing our own minds. The danger lies not in revealing our hand, but in not having one.