The principle of checks and balances prevent a monopoly of power from happening. It avoids a government where a single body can decide on practically anything without a check from another. Gridlock may be present, but it is better as to check for possible abuse of power by the government in a parliamentary government.
Any form of military intervention would lead to chain of conflict. Syria and its allies will retaliate against an attack. Consequently, an attack against US allies would also trigger another attack. A scenario which world war 3 is possible.
Threaten to attack if more chemical weapons are used.
A military threat from the US, forces Assad to surrender his chemical weapons. This means that a threat is very effective to prevent further casualties due to chemical weapons. Threat, however, should not be materialized as to prevent a possible retaliation against the US and Its allies.
War will make a country powerful and rich. When there is war, a lot of industries are moving to manufacture weapons to sustain the needs of the soldiers. Also, many people are employed by these industries, thus unemployment is solved.
For example during the American Civil War, there was a drastic improvement on the United States because of it. As both the Union and the confederate fought hard on battlefield, dead industries were revived- economy boost. Also, the number of soldiers increased that make what the US it is today.
Generally, people die in war but if it's meant to defend to preserve peace, then I go for it.