Dov Zakheim comments indirectly on the debate over pursuing regime change in Syria:
First, regime change hardly began with Milosevic or Saddam; what were the fall of the two Napoleons in 1815 and 1870, respectively, if not regime change? Both world wars also brought regime change, as well as the creation of new states.
Zakheim is right that policies of regime change did not begin in the last twenty years, but these are not the best examples of what he means. Removing Napoleon from power became the Coalition’s goal because it was necessary for ending the war with France, but the Coalition’s members hadn’t originally been at war with France in order to topple Napoleon. The French revolutionary regimes of the 1790s and the First Empire pursued policies of regime change to install governments that were aligned with Paris. Napoleon III was captured by the Prussians, but the Prussians hadn’t set out to depose him. His rule was discredited by military defeat, which provoked a domestic revolution against him, but it’s not as if Bismarck’s goal had been to support French republicanism. For his part, Napoleon III had pursued an earlier policy of regime change in Mexico to install a French-backed puppet ruler there. It is typically colonialist or revolutionary states that seek regime change as their primary goal, because they see individual regimes or types of regimes as impediments to their territorial expansion and/or ideological success. Both types of governments seek to topple local governments and install friendly or puppet regimes, or they sometimes eliminate the other state entirely and absorb its territory.
WWI caused many regimes to fail and collapse, and the belligerents desired the destabilization and collapse of their enemies, but overthrowing enemy governments was not the original goal of any of the belligerents (except maybe Austria). If it happened, it was useful because it was a means to an end (e.g., forcing Russia out of the war to free up German resources for the other fronts). WWII was a bit different. The war resulted in the collapse of the Axis governments and their collaborationist satellites. At least two of the Axis powers were intent on toppling other governments to serve their expansionist policies (not exactly the most attractive precedents). However, on the Allied side the destruction of the hostile regimes was bound up with seeking total victory in a conflict whose origins had been very different. As far as the U.S. and the USSR were concerned, WWII was a war of retaliation and self-defense.
What distinguishes modern policies of regime change from Zakheim’s examples is that regime change is now frequently promoted as an end in itself. Advocates of regime change may claim that a policy of regime change will have various secondary benefits, but the overriding concern is simply to be rid of the current government of another state. While other governments have been targeted for destruction in wars that have other causes, modern policies of regime change are different in that they often involve fighting wars and/or engaging in subversion for the primary purpose of destroying another government. Another thing that distinguishes modern policies of regime change from Zakheim’s examples is that all of the regimes targeted for it in recent decades were targeted largely because of things they were doing inside their own borders.