Sept 2 (Reuters) - Here is a snapshot of Reuters news about the crisis in Syria:
* President Barack Obama wins the backing of the leaders of both parties in the House of Representatives for his plan for limited U.S. strikes on Syria to punish President Bashar al-Assad for the alleged use of chemical weapons against civilians.
* A resolution authorizing the use of military force in Syria will likely pass the U.S. Senate but not without specific changes, the head of the Senate Foreign Relations Committee says ahead of a hearing to consider U.S. plans.
* France will step up aid to Syria's opposition if the United States Congress votes against a military strike to punish Syria's president for carrying out a reported chemical attack, President Francois Hollande says.
* Israel tested a U.S.-backed missile system in the Mediterranean on Tuesday, but did not announce the launch in advance, prompting disclosure by Russia that put the world on edge as the United States weighed an attack on Syria.
* A Syrian forensic medicine expert with evidence that Assad's administration used chemical weapons in an attack near Aleppo in March has defected to Turkey, the Syrian opposition says.
* Assad denies his forces were behind the attack and has warned that French military action would lead to "negative repercussions."
* More than 2 million refugees have now fled Syria's civil war in human suffering unparalleled in recent history, the United Nations says.
* Syrian forces seized the strategic northern town of Ariha on Tuesday, an opposition group says. This would open the supply line between the coastal stronghold and pockets of army control in a region that is largely rebel controlled.
* Obama's decision to wait for congressional approval for a strike on Syria has sharpened the view of the United States as a hesitant superpower just as he prepares to go to Sweden and Russia this week.
* Shifts of power and money - led by capital flight from emerging markets - and gaping divisions over Syria will test the resolve of G20 leaders when they meet in Russia's second city of St Petersburg this week.
* Russia criticised the United States on Tuesday for sending warships close to Syria, saying the deployments would exacerbate tensions.
* The U.S. military's decision to move an aircraft carrier into the Red Sea to help out with any "contingencies" underscores concerns that a strike on Syria could evolve into another costly war as U.S. defense spending faces massive, mandatory cuts.
* "What we are envisioning is something limited. It is something proportional. It will degrade Assad's capabilities. At the same time we have a broader strategy that will allow us to upgrade the capabilities of the opposition," U.S. President Barack Obama.
* "The Middle East is a powder keg and the fire is approaching ... We shouldn't just talk about a Syrian response, but what will happen after the first strike. Everybody will lose control of the situation when the powder keg blows." - Syrian President Bashar al-Assad to French newspaper Le Figaro.
* Obama departs late on Tuesday for Sweden and a two-day G20 summit in Russia that starts on Thursday. (Compiled by David Brunnstrom)