@Rancid
Let's say you are right. What do you think will come in its place?
In Iraq, the people are already moving and nominating technocratic and independent elements and candidates to take over the government in the massive protests in the country.
In Iran, the reformists' faction with the various socialists and federalist elements have been fighting for decades and will take over the moment the regime falls.
In Lebanon, there are already many names demanded to take over the government by the protestors and the people in general like Nawaf Salam for example. Primarily, technocrats and democrats.
The only wild card is Syria as it's a Russian puppet primarily and not an Iranian one (for the most part).
In Yemen, there is already a government in place combining all elements fighting the clerics' proxies.
In Libya, there is already a national government supported by many countries fighting against Iranian and Turkish backed proxies.
The point is, there won't be a power vacuum.
We're not talking about a regime change where there are no alternative, we're talking about a regime spread across multiple countries falling apart due to internal revolution and uprising by the people and opposition factions.
The reformists in Iran aren't new, we've been fighting them for decades now.
The opposition in Lebanon and Iraq isn't new either.
Worst case scenario for Iraq is the Sadrists, an enemy of Iran, taking control; and those aren't all that bad, or bad at all.
Worst case scenario for Lebanon is that the powers of 14th coalition (Edit: 14th of march coalition) taking control, and those have a wide public support and are, in most cases, loved by the people; The likes of Hariri, Samy Jmail, Walid Junblat, Michel Daher, Michel El Murr, etc.
@blackjack21
Trump's role is insignificant, so as the American role in general.
The revolution is internal by the masses of people sick and tired of them and their tyranny after this many decades.
@Rugoz
It made it through many decades of sanctions because everyone united behind the flag if so to say, but not anymore.
The clerics have, in the past 3 years, have cut or eliminated almost all welfare programs, cracked down on the reformists factions, and have antagonized all major tribes, antagonized and are starting a fight with the Kurds and Azzaris, and have made living conditions miserable for the Balochi, Afghani, and southern Tribal peoples in general.
10 years ago, Iran was politically divided, sure, but everyone inside was forcibly united by the Americans as a common enemy; That is no longer the case, and the clerics even lost a massive portion of their public support in the past years as they've run the country to ruins starting with their own base.
EDIT:
May I also add that although Syria is a wild card, it's unlikely for the regime to survive if both Lebanon and Iraq turned against it as the opposition in Syria is already pretty pissed about the massacre going on in Idlib and a political shift in Iraq and Lebanon could see a renewal of efforts and support to remove the regime by force.
It ofcourse remain a wild card as Syria is not even close to being a single nation and a collapse of the military regime would most likely lead to an even bigger civil war the would end either in a forced federalization or all out partitioning of the country along the axis of North, south, coast, eastern tribes, and Kurds. (5 smaller nations basically).