UNITED NATIONS, June 12 (Reuters) - Escalating violence in the Golan Heights is jeopardizing a four-decade old ceasefire between Israel and Syria, UN Secretary-General Ban Ki-moon said in a report to the UN Security Council on Wednesday.Ban recommended that adjustments be made to a UN peacekeeping mission in the area, known as UNDOF, including "enhancing the self defense capabilities of UNDOF, including increasing the force strength to about 1,250 and improving its self defense equipment."