Addressing the Disabled American Veterans' national convention on Aug 2, Obama reiterated that US combat mission in Iraq would end on schedule, that is, on Aug 31, and the remaining US troops would be engaged only in diplomatic-led efforts.

The US invaded Iraq in 2003, and its troops there once grew to 140,000. But after taking office, President Obama shifted US focus from Iraq to Afghanistan and gradually reduced the number of American troops in the Middle East country.

At present, there are 80,000 US troops in Iraq but their number will be reduced to 50,000 by the end of this month. The remaining troops will continue to train Iraqi security forces, conduct counter-terrorism operations and protect supplies.

This has made many analysts say that Obama wants to use the progress he has made in Iraq to regain support for the Democrats in the November mid-term election. But he fears that Iran could seize the chance to fill the "vacuum" created by the US troop pullout from Iraq.

The political situation in Iraq is fluid. A new Iraqi government is yet to be formed, even though the parliamentary election was held on March 7. If Iran were get to more deeply involved in Iraq, the situation there could only worsen.

Therefore, it seems Obama might have sounded out Mullen to issue a warning to Iran (a deliberate act to warn his opponents, too) and only after that he reiterated that US troops would be withdrawn from Iraq on schedule.

Analyzing US policy on Iran, the ORG report says that "while the Obama administration seems unlikely at present to consider military action, its rhetoric has certainly become far tougher". This in effect means despite issuing a strong warning to Iran, the US won't launch a military strike against it in the immediate future. The new sanctions on Iran, declared by the US on Aug 3, targeting senior officials of three organizations and 21 companies, partly conform to ORG's conclusion.

The US is not likely to attack Iran for now, but can the same be said about Israel? On Aug 3, the Veteran Intelligence Professionals for Sanity submitted a memorandum to Obama, reminding him of the possibility of an Israeli attack on Iran without consulting the US. The memo said that Israeli leaders were confident that the Jewish lobby would influence the outcome of the US mid-term election and Israeli Prime Minister Benjamin Netanyahu might be compelled to believe that if Israel launched a pre-emptive attack on Iran, the US would have no option but to support it.

Such a development may get the US bogged down in an even bigger war with dimmer prospects. So, Obama should condemn such a move before it becomes reality. So, the Obama administration may not upgrade its warning against Iran further, or else the situation would spiral out of its control.

The author is a professor at China Foreign Affairs University.