The extended security cabinet, numbering 13 government ministers, sat for about four hours this morning, hearing details of the non-stop Palestinian violence and discussing possible reactions. Several ministers demanded that the government intensify its offensive measures; Foreign Minister Shimon Peres objected, and has even threatened to quit if such an approach were to be adopted. \"I am not Ariel Sharon\'s clerk,\" Peres said last night. \"He won\'t tell me what to do.\" Reports from the meeting say that the offensive measures will be intensifed, but not signifcantly so.