Seven Azeri soldiers and a civilian and four Armenian servicepersons were killed on Tuesday in the third day of border clashes between countries that fought a war in the 1990s over the mountainous Nagorno-Karabakh region.

The international community worries about clashes between Armenia and Azerbaijan in part because of the threat to instability in the South Caucasus, a region that serves as a corridor for pipelines taking oil and gas to world markets...