NEW YORK — The world may be focused on the big fight in Syria between the rebels and Bashar al-Assad’s regime, but there is a smaller, albeit just as significant, second front going on.

Though many of the region’s leaders seem to have either ignored or forgotten it, the second fight in Syria is taking place among opponents of the Syrian government.

Editor's Note: Nicholas Burns is GlobalPost's senior foreign affairs columnist. He writes a bimonthly column on the international issues that shape our world.

CAMBRIDGE, Mass. — President Obama is right to respond cautiously to accumulating evidence that Syrian dictator Bashar al-Assad used chemical weapons against his own people. After all, if we learned one thing from the Iraq War, it is that the United States must be absolutely certain of the facts before we launch military action against another Muslim country.

CAMBRIDGE, Mass. — Historic Copley Square is one of my favorite places in my adopted city of Boston. This is where, last month, we held a vigil against Shia killings in Pakistan. This is where runners at the Annual Patriots’ Day Marathon cross the finish line at Boylston Street, right past the majestic public library.

And this is where, on April 15, two bombs exploded, disrupting the idyllic scene of the marathon on a crisp, sunny Monday afternoon.

CORTEZ, Colorado — World Malaria Day draws our attention to the grim fact that about a million people die every year from malaria in Africa, most of them children. Malaria also is a preventable and treatable disease.

The US Agency for International Development has a strong and growing program to fight malaria in Africa, but a way must be quickly found to avoid its collapse due to the recurring development of insecticide resistance by the mosquitoes that transmit the disease.