War or talks... What’s next?

The Middle East has once again become the focus of the whole world since Jan. 3, 2020.
The killing of Qasim Soleimani, the head of the Islamic Revolutionary Guards Corps' elite Quds Force, and Abu Mahdi al-Muhandis, a senior commander of Iraq's Hashd al-Shaabi, or Popular Mobilization Forces and those accompanying them, at the Baghdad Airport on U.S. President Donald Trump's orders have made the long-standing tensions between Iran and the United States the important issue in world politics.
Surely, this death raises many questions, to which we might never know the answer, meticulously assessed by Iranian and American officials: Was the real target of U.S.'s Hashd al-Shaabi?
Was Qasim Soleimani known to be in the convoy and ordered to be killed, or was it learned after the attack?
Did the U.S. provide this intelligence on its own or receive it from somewhere else? And if it received the intelligence from elsewhere, was the U.S. misled?

Another question lingering on everybody's minds is: So, what now? In order to answer this, we must understand how the current phase has been reached and what the parties expect from each other.
The decision of the U.S. to withdraw from the Joint Comprehensive Plan of Action (JCPOA) in May 2018 and its listing of Iran's Islamic Revolutionary Guard Corps (IRGC) as a terrorist organization in April 2019 formed the basis for today's conflict.
However, the death of an American contracted civilian personnel in a rocket attack on the military base in Kirkuk, where U.S. soldiers were present as well, on Dec. 27, 2019, and the killing of Soleimaini as a response by the U.S. became one of the main breaking points.
Another significant development occurred on New Year's Day when thousands of people...