( CNN ) -- As the scale of the humanitarian crisis in Syria mounts , so have the calls for military intervention . Bashar al-Assad 's regime has been brutal , calculating and impervious to world opinion ; with the assistance of Russia and China , it has dodged a U.N. mandate to halt the attacks on its own people . The now-familiar pattern of the Arab Spring -- popular outcries for freedom provoking hideous repression , which we saw in Libya in 2011 -- seems to warrant military intervention to stop the slaughter in Syria . But first we need answers to some hard questions . Please . We have just exited Iraq after 8Â½ years , a cost of more than $ 1 trillion and a loss of some 5,000 U.S. service members . And Iraq is still a cockpit for sectarian struggle and violence . In Tunisia , Egypt and Libya , strong Islamic sentiments have inevitably surfaced despite the democratic and Western-oriented facade of the initial Arab Spring uprisings . The future orientation of these states is likely to be less helpful to U.S. aims and policies in the region than their predecessors . And overshadowing Syria is the worry of Iran 's nuclear ambition , and the fact that `` all '' options must be kept available in case diplomacy fails there . So , in the case of Syria , we must ask , first , what are the U.S. national interests at stake ? What is our objective ? Then , how would the use of force attain that objective ? How much force , how applied , at what cost ? What is the end state we seek ? What basis in international law is there for action ? Which allies will help us ? And , when all is said and done , have we actually achieved what we set out to do , and at a cost and risk proportionate to U.S. interests ? In addition to humanitarian concerns , there are significant U.S. strategic interests at play in Syria . The Syrian regime is a `` front-line '' state to America 's ally Israel , and so is critical to lasting peace there . And while the Syrian regime has flirted with a peace agreement , it has also served as a conduit of Iranian influence and threats . McCain calls for airstrikes on Syria . Syria hosts Iranian advisers and assists Hezbollah , an Iranian-backed fighting force that has squeezed and threatened Israel from the north , provoked one border war already , taken a powerful and coercive role inside neighboring Lebanon , and which serves as a major factor of regional intimidation as Iran angles to attain its nuclear aims . Moreover , the Syrian regime is a Cold War relic , maintaining a strong military and inviting ties with America 's geostrategic competitor , Russia . Unlike the case of Libya , the United States has substantial strategic interests in Syria but would be facing a strong , capable military still mostly loyal to al-Assad . Syria is less accessible militarily than Libya , with a population triple its size -- 22 million , including some 2 million Christians . Opinion : World should n't stay silent in face of regime 's brutality . Weapons are flowing in , refugees are fleeing , but there seems to be little in the way of an organized Syrian opposition with which to work . And while Saudi Arabia and Qatar are calling for al-Assad 's removal , this seems more of an opportunistic anti-Iran strategy . Among the resistance forces are apparently some radical Sunni fighters , perhaps al Qaeda itself , and others whose ascension to power would likely cause a further crisis , with millions of Christians and other religious minorities fleeing from the region . While the U.S. aim in ending the violence and saving lives is obvious , this is a much more complicated and demanding scenario than Libya . There is as yet no international mandate , not even from NATO . The most appropriate form of intervention is reportedly under study -- but it looks like almost any course of action will increase the violence , not reduce it . And who will be available in the skies and on the ground to help ? How will a new government be formed , and how will Syria be managed until then ? What is needed right now is clear thinking , solid planning and a well-supported international strategy for the region , including Iran -- before we act . The opinions expressed in this commentary are solely those of Wesley Clark .
Wesley Clark : The calls for military action to stop Syria slaughter are understandable . He says there are a host of unanswered questions to deal with . But he also points out that the US has been involved in Iraq and Afghanistan, which is not an ideal situation. Clark : It looks like every course of action would increase , rather than curb , violence .