Israel's main backers in the US are putting public pressure on USbr President Barack Obama demanding that he harden his stance withbr regards to the Iranian nuclear program and for the US to be morebr forthright in supporting Israel in its own confrontation with Tehran.br This comes ahead of Prime Minister Netanyahu's visit to Washington whobr will deliver a similar message to the President when they meet at thebr White House on Monday. According to some, Netanyahu brings with him anbr ultimatum, demanding that unless the president makes a firm pledge tobr use US military force to prevent Iran acquiring a nuclear bomb, Israelbr may well take matters into its own hands within months.