Speaking to foreign policy experts at a Nato conference in the Latvian capital Riga on Saturday, Bildt and his Polish counterpart Radoslaw Sikorski warned against knee-jerk reactions.
"Let's be realistic. We have an escalating civil war in the entire Levant... The only thing I can say that would have any reasonable chance of success would be to go in with armies and stay there for 30 years and try to do some real nation building. Appetite for that? Non existent," Bildt said, according to AFP.
"It is an immensely complex problem. There is not a simple solution. We will have, on the European side, to stay engaged with this part of the world for decades to come in every single respect," he added.
Poland's Sikorski for his part talked about the importance to "think about the consequences before we plunge in" and pointed to previous Western interventions in Lybia and Iraq as reason for caution, AFP writes. "Do you really want another Iraq? Was that such a good idea?" he asked rhetorically.