It's a nice spring day on May 23, 2016. You sit outside with a radio and tune in to the news. In the middle of hearing the station talk about [insert politician here], you hear a large burst of static. Simultaneously, every television set and radio on Earth has the same burst of static. After a few seconds, the static fades away and 7 billion people hear an unfamiliar voice.
"We are representatives of the species qponvuiphzpoi, from what you call the Rigel star system. We have a material, Unobtanium, which has an infinite energy density, allowing for faster-than-light travel and unlimited, clean energy. However, the human race needs to prove that it is ready for this technology. Your species is engaged in perpetual warfare, and you kill your neighbors senselessly. To prove that you are ready, you must cease all warfare within one Earth year, or else we will leave and see if you are ready 10,000 years from now. We will be watching."
TL;DR- you can get Unobtanium if you stop all wars.
Would we be able to stop fighting in time? This is especially complicated in the Middle-East, where conflicts have been going on for centuries. This is magnified by the fact that much of their economy is based on oil, which the Unobtanium would make obsolete.
The aliens will use this definition of war:
A state of armed conflict between different nations or states.
I'll expand that to include the definition of a civil war:
A war between citizens of the same country.
In unclear cases, assume that the aliens have their own judgment. If most people think it's a war or civil war, the aliens also do (no using this as a loophole). The definition of war isn't the point of the question.
Syria = War
ISIS = War
Gang violence ≠ War
Assume that the aliens have some sort of cutoff switch for the Unobtanium, at least initially, to make sure that humans keep their promises for a while.