The Pentagon says it's "ready to go" if it gets orders to carry out a military strike in response to Syria's suspected use of chemical weapons against its own people.
Most people know Syria's civil war has been raging for more than two years. But the situation is so complicated that it's hard for even the biggest news junky to keep track.
Now that Washington is seriously thinking about ordering limited missile strikes in one of the most volatile regions of the world, it's a good time to retrace events and remember how we got here.
Here's a quick-read cheat sheet about the Syrian civil war. It's not intended to be an all-encompassing encyclopedia, but it will bring you up to date on what's really important about a scary situation in an already volatile part of the world.
1. What did Syria look like before the conflict?
Even before the uprising in Syria, things weren't peaceful there. Discontent simmered for decades.
In 1982, President Hafez al-Assad clamped down on a Muslim Brotherhood uprising. In one attack, his iron fist left tens of thousands dead.
When Hafez al-Assad died in 2000, his son, Bashar al-Assad, took over the presidency. He promised to build a more modern and democratic nation.
But reforms didn't come fast enough for activists -- who called for change and slammed Syria's government as an "authoritarian, totalitarian and cliquish regime."
Sectarian and ethnic unrest shook Syria during the past decade, too. A Druze uprising flared in 2000 and a Kurdish rebellion erupted in 2004.
2. How did the civil war begin?
It all started in February 2011 in the city of Daraa, when authorities arrested 15 schoolchildren for painting anti-government graffiti on the walls of a school. The children didn't mince words with the message they painted: "The people want to topple the regime."
Word spread that the children were allegedly mistreated while in custody. Outrage over their arrest grew -- fueling protests.
Security forces opened fire, activists say, killing at least four protesters.
These four -- activists say -- were the first deaths in Syria's civil war.
Within days, according to Human Rights Watch, protests grew into massive rallies made up of thousands.
Their rallying cry: "Daraa!" -- the city whose children sparked a national movement.
3. How did the unrest turn into a call for an end to al-Assad's rule?
It didn't take long for al-Assad to criticize protesters in Daraa. In a March 2011 speech before lawmakers, he said "conspirators" started out there and wanted to spread unrest.
His dismissive remarks -- and the way lawmakers applauded afterward -- only further fueled protests.
"That speech had a catastrophic impact," the International Crisis Group's Peter Harling told CNN last year. "People who wanted to support the regime at the time were shocked."
Two days later, weekly anti-government protests began across Syria. Calls for reforms soon escalated into calls for the removal of the entire al-Assad regime.
Now, armed rebels have vowed to accept nothing less than al-Assad's ouster, while the Syrian government has labeled them terrorists and vowed not to back down.
The United Nations estimates that the fighting has claimed more than 100,000 lives.
4. OK, but that all started more than two years ago. Why do some people think the United States needs to take action now?