Twitter has become an indispensable diplomatic networking and communication tool. According to the new study Twiplomacy, more than half of the world’s foreign ministers and their institutions are active on the social networking site. Here are five lessons from our world leaders on Twitter.

Unfortunately, there’s a long history of terrorism. Palestinians regarded it as a resistance to what they see as an illegitimate occupation. Of course, Israelis regarded it as terrorism. What I think is new here, which is very troubling, is that people are using the new tools of technology, social media, and you're beginning to see radical fringe elements that are able to organize, galvanize support.

As negotiators from Iran and the P5+1 nations meet behind closed doors in Vienna in a final push for a comprehensive nuclear deal, a separate round of negotiations is taking place online. Secretary of State John Kerry and his Iranian counterpart, Foreign Minister Javad Zarif, traded accusations, praise, and hopeful words in advance of the final round of nuclear negotiations. The two sparred in a pair of op-eds published in the The Washington Post (Kerry) and Le Monde (Zarif), and in a video Zarif made available on YouTube. 

In the wired age, "Twitter bombs" that spam feeds with militant propaganda are as much a part of the modern jihadi’s arsenal as bullets. But with every burst of online messaging from extremists comes potential blowback.

If you’re a Russian citizen these days, it is easier than ever to support the insurgency in eastern Ukraine, now nearly three months old.  With the click of a mouse, you can transfer money through Sberbank – Russia’s largest bank, which is government controlled – to grassroots organizations supplying separatist rebels with weapons and personnel.

Google’s motto is “Don’t be evil.” Can the company practice what it preaches – even in Cuba? A delegation of Google employees, headed by executive chairman Eric Schmidt, traveled to Cuba this past week in an effort to advocate for removing government restrictions on the Internet. The executives met with Yoani Sanchez, a prominent blogger and dissident who runs the independent 14ymedio news portal, a site blocked in Cuba.

The Islamic State of Iraq and Syria has taken to Twitter to spread its message, trumpet bloody successes, and recruit potential jihadists, but its social-media campaign has come under attack from forces that range from the U.S. State Department to the mysterious group of hacker-activists who call themselves Anonymous.