One perennial argument in international relations is that between realists on the one hand and idealists and constructivists on the other. Idealists believe in the perfectability of humankind and in the ability to interject moral and ethical authority into international affairs. Both Jimmy Carter and George W. Bush adopted this approach to US foreign relations, Carter with his human rights policy and Dubya with his Pax Americana doctrine for transforming the world into the neoconservative’s preferred image. Closer to home, the Lange government’s non-nuclear declaration appealed to the higher minded elements in the global community.
Constructivists are not as prone to believe in the power of moral authority in international affairs. Instead, they believe that the behaviour of international actors can be constrained and regulated  by international norms and institutions. New Zealand’s support for multinational institutions and multi-lateral approaches to international conflict resolution, as well as its support for  international norms such as those embodied in the nuclear Non-Proliferation Treaty (NPT), are examples of constructivism in foreign policy. Idealists and constructivists dovetail in their belief that multinational institutions and norms can promote better international behaviour than otherwise would obtain.
Realists do not believe this is possible. Realists operate on the premise that because there is no moral, ethical or ideological consensus in international affairs, and because there is no superordinate authority to consistently and effectively enforce its rules of conduct, then the world is effectively in a state of nature (as used by Hobbes). Absent Leviathan in international affairs, states and non-state actors pursue their interests checked only by the relative power of other actors. Self-interest, not morality, rules the day. Classical realists see war as a systems regulator and military force as the ultimate determinant of power. Neo-realists (who emerged in the late 1970s and 1980s) believe that economic power is more important than military might and that the exercise of economic power determines the ability of actor’s to project force in defense of national and self-interest. They used the example of the USSR as a case where military power did not equate or supersede structural power in the long-term course of foreign affairs.
For realists international norms and institutions are nice and ideally preferable, but are no substitute for self-interested power projection as the basis for international stability. Realists see a place for idealist-based international institutions and norms in peripheral areas of international behaviour, but not in core areas of national interest. Thus saving whales can be approached via constructivist means, but securing trade routes and borders cannot.
In the realist view, international actors need to fend for themselves in the last instance, and therefore should approach the global arena with a view to best defending their own interests rather than those of the world community as a whole. Where national power is insufficient to defend core interests, alliances are constructed to do so. Contrary to the perception that realists are military hawks, realism is risk and war adverse in any circumstance where core national interests are not at stake. They do not believe in perfectability campaigns such as democracy and human rights promotion, nor do they believe in wars of choice fought to promote a preferred political outcome or moral ideal. Realism, at its core, is pragmatic and self-limiting.
The Syrian crisis has shown that when it comes to enforcing international norms the global community does not have the will or capability to do so. The bulk of world opinion is against US military intervention to punish the Assad regime for using sarin gas against his civilian population (not once, but a total of at least eleven times in the past 18 months). This occurs in spite of the 1927 and 1993 international bans on chemical weapons and the 1997 international convention calling for the destruction of all chemical weapon stockpiles. The political leadership of the majority of nation-states oppose the use of force to punish Assad for his war crimes (I will leave aside for the moment the question of who did the gassing, as the focus here is on international norm violations). Amongst those who believe that Assad should be punished (including the National government), only France appears willing to go to war. Even the US Congress is divided on the issue.
That is striking. The ban on chemical weapons is one of the oldest international conventions. It has obvious moral weight. It has been ratified by over one hundred countries. Images of the victims of the latest attack have been compelling and transmitted world-wide. One would think, if idealists and constructivists are correct in their views of the international community, that Assad’s transgression of such an important norm would prompt a call to arms by fair-minded people the world over. Yet it has not. To the contrary, it has elicited apathy, denial, disinterest or fretful handwringing by the world at large.
What this demonstrates is that when push comes to shove, pragmatism and self-interest trump idealism and constructivism in world affairs. While seemingly promising on the surface, the Russian proposal to have Syria hand over its chemical weapons to the UN can also be seen as a cynical ploy to give Assad some time to disperse his chemical weapons stores while continuing his counter-offensive against the rebels by conventional means (which the Russians are supplying). I say that because ensuring the transfer of Syria’s several thousand tons of chemical agents will be lengthy and exhaustive process that will require thousands of foreign technicians on the ground in Syria, and assumes perfect cooperation by the Syrian authorities and the rebels in the midst of a nasty civil war. That is an optimistic view at best, and something that idealists and constructivists may believe possible if a negotiated settlement can be reached under the auspices of the UN Security Council.
However, the Russians are no idealists when it comes to foreign relations and international affairs. Instead, they are very much informed by realist notions of inter-state behavior, so it is safe to assume that their proposal has less to do with humanitarian concern and more to do with Russian power projection and strategic interests in Syria and beyond.
One could argue that the same is true for the US and its allies, and that the call for military intervention by the US against the Assad regime has little to do with humanitarian concern or international norm enforcement and more to do with the geopolitical competition between Iran and its proxies (including the Assad regime) and the Sunni Arab world and the West. This view is backed by the misuse by NATO of the Responsibility to Protect (R2P) doctrine to justify the Libyan intervention. Under R2P foreign military intervention is justified in order to protect vulnerable populations from the depredations of their governments or in the face of government incapacity to defend them against the violence of others. But in Libya it was used as a pretext for forcible regime change over the objections of the Russians and Chinese. Given the outcome, that has for all intents and purposes killed off R2P as an international norm.
The situation with enforcing the norm against use of chemical weapons is even more fraught. Besides the reluctance of the global community to enforce a norm in a conflict in which most have no strategic stake, there is the problem of its prior unsanctioned use. Not only did Saddam Hussein use chemical weapons in the Iran-Iraq war (with the CIA providing targeting data to Iraq fully knowing that Saddam intended to use chemical weapons against Iranian troop formations). More recently Israel has used white phosphorous (another banned agent) in Gaza and the US used white phosphorous in the Battle of Falluja. In both cases the dense urban combat environment made it impossible to discriminate between civilian and military targets, so their use was arguably criminal even if there were not a ban against them.
In each of these instances the perpetrator used chemical weapons because it was felt to be expedient and because they could get away with doing so. Although there was some hue and cry about their use, no effective action was taken against any of these perpetrators. Only later, in the first Gulf War, was Iraq’s prior use of chemical weapons used to justify the military response to his invasion of Kuwait (and even then his suspected chemical weapons stockpiles were not destroyed by Desert Storm and the US-led alliance refused to help the Shiia uprising against him in the wake of his defeat).
Israel and the US have paid no price for having used chemical weapons in recent years.
Moreover, in spite of the 1997 convention on destroying chemical weapon stockpiles, it is widely believed that most countries that had them at the time (including the US, UK, Israel and Russia), failed to completely eliminate them from their respective inventories. Others, such as Syria, never signed up to the chemical weapons ban and thus have proceeded to develop that capability as a deterrent and a hedge against conventional military defeat.
All of which to say is that at least when it comes to the ban on use of chemical weapons, idealists and constructivists have been proven wrong and realists have been proven right: besides the strategic calculations of many nations that advise against involvement in the Syrian conflict, regardless of the outcome the international norm against using chemical weapons is not worth the paper it is written on. It is, as they say in Spanish, letra muerta.