The maximum time limit for middle east to flare up is the time Iran needs to build their bomb. As by then the allies have to bomb Iran anyway.
Right now the situation is tense. But might not roll out to war. When the time is ripe you would know it beforehand watching war machine concentration.
The world right now is in a stand still. Both sides know the consequences and they are working hard to figure out a way that will work. How much that works is something to be seen.
Note that nothing of these would have been possible, had Trump stuck to Obama's agreement.
So how much time would Iran need to make the bomb? A few days ago Iran declared it's purifying U235 to 20%. That's the threshold after which purifying speed boosts up rapidly. And Iran said it can build a million centrifugal machines if necessary. Pre-contract it had 30,000.
I would give it two more years.