Iran has demostrated poor behavior in the middle east for decade's by funding and supplying several terriost groups.
With our battle group there a attack on them will result in as we say in America the poop hitting the fan be it a direct attack by iran or thier proxy forces.
Also attacks on our allies in the region such as the recent attacks on the saudi oil pipe line or a attack on Isreal could result in s few Arleigh Burke Destroyers and a nimitz class carrier raining down hell on a few targets or more.
Now 3 of the most powerful forces in the region the saudis Isreal and Turkey really dont care for Iran.
i doubt russia one air craft carrier wants to face off with our 19 and our ground air powet along with the saudis Isreals and turkeys.
Russia has a sizable military but its out of date and poorly funded. Ours is very modern well trained and a budget several times as large allowing extend fighting for years .
Putin puts on a good show buy I doubt he wants to go head to head with us.
Now iran has a habit of taking action and blaming its proxy army the rebels in yeamen the plo and hamas and anyone they can.
Iys a dangerous game and they stand to suffer for it should they take action.
Now trump has no desire for a war at all and has said as much .
But not having a desire for a fight is one thing getting bitch slapped and backing off is not his style jelly legs obama is no longer in charge.