We have already seen the first shots fired.
In February, Iran sent a drone into Israeli airspace, Jerusalem responded by hitting a Syrian air base used as an Iranian command and control centre.
Just last week, the same air base was struck, killing Iranian military advisers.
Israel is believed to have carried out the attack, but there has been no confirmation or denial.
Middle East analysts are fearing a full-blown war between the two.
Syria ‘starting to resemble a world war’
Jonathan Schanzer from the Foundation for Defense of Democracies has warned of what he says, “could be the ugliest Middle East war of the 21st century
Last week, he told ABC News program Matter of Fact the Syrian conflict was beginning to resemble a world war.
Iran ’emboldened’ after nuclear deal
Friedman says Iran is, “the biggest ‘occupying power’ in the Arab world today”.
It is already fighting a war in Yemen, supporting rebels, that pits it against another of its declared foes, Saudi Arabia.
And, of course, it is mired in the Syrian conflict.
That position has strengthened with the appointment of America’s former UN ambassador, John Bolton, as the new White House National Security Adviser.
Mr Bolton has in the past advocated for pre-emptive action against Iran.
He said simply: “Our goal should be regime change in Iran.”