This week, Congress is expected to vote on a measure to authorize President Obama to launch an attack on Syria, in response to the use of deadly sarin gas in Syria’s two-year civil war. Strong opposition to the attack is emanating from both edges of the political spectrum. While this authorization is the right thing to do, the issue is nevertheless complex and requires a degree of clarity and nuance that seems to be missing from our national discourse.

Opponents of the strike have questioned whether we can really trust intelligence that blames Bashar al-Assad, Syria’s president, for the use of sarin gas. Indeed, it was flawed intelligence that led the United States into the costly war with Iraq. But we must also remember that despite its failings, American intelligence is also exceptionally capable — it was this same intelligence community that located and killed Osama bin Laden, for example. Ultimately, without access to classified materials, no private civilian — including myself — can accurately determine the quality of the intelligence. We are left to place a degree of trust in the commander in chief, a trust that must transcend partisanship.

Others have pointed out that Assad’s enemies, who would benefit from an American attack, are not friendly to the United States and have themselves engaged in brutal war crimes, including gruesome executions and even cannibalism. This is almost certainly true. But the purpose of the American attack is not to establish democracy in Syria but rather, to respond to Assad’s indiscriminate use of sarin gas on civilians. Sarin gas, developed in Nazi Germany, is odorless, and a pinprick-sized droplet of it can kill a person.  It’s impossible to even imagine the terror this must have caused Assad’s many victims, who slowly suffocated to death in their hometown.

There remains an open question about what exactly the Syrian strike will entail. What are the targets? How long will the operation last? Naturally, these are sensitive questions, and America’s military leaders should not discuss this information publicly prior to an attack. Instead, Congress should narrowly tailor its resolution to provide for a limited engagement that does not involve the use of ground forces in Syria.

Some commentators have said that because America itself has used chemical weapons and that the United States has not responded to other uses of illegal weapons, we are in no position today to respond in this instance. This ignores our modern moral imperative. Hypocrisy is no excuse for inaction, especially when the stakes are this high.

Finally, the importance of this operation should also be viewed in the context of Iran, Syria’s foremost ally. Iran is the world’s largest state-sponsor of terrorism, is openly building a nuclear bomb, and has routinely threatened to attack the United States. Inaction on Syria sends a message to Iran that the United States is unwilling to engage in the Middle East, even in the face of grotesque and blatant violations of international law. While some have questioned whether an attack on Syria would be in America’s interest, virtually all commentators agree that a nuclear-armed Iran would be a serious and dramatic blow to American national security.

What President Obama has proposed is not without risks, costs, and uncertainty. The vigorous debate of the last week is entirely appropriate. But amid this discussion, we must remember that failing to respond to the use of sarin gas would send an atrocious message and would embolden America’s most potent national-security threat — Iran. Congress should approve this measure as soon as possible, and Obama should know that the American people will be watching very closely.

Dan Garon