Rukmini Callimachi, a foreign correspondent for The New York Times, has reported on the Islamic State group without holding back. Callimachi has exposed how the terrorist network mistreats women and children, including trafficking them as sex slaves, and her clear and informative journalism has helped Americans understand the dire situations ISIS has created in Iraq, Syria, and beyond. After President Obama addressed the United States from the Oval Office Sunday night about the current terrorism threats to America and the world, Callimachi fired off a 19-part tweetstorm that breaks down the complex crisis created by ISIS. Obama encouraged Congress to authorize the use of weapons in Iraq and Syria to fight ISIS. "The threat from terrorism is real, but we will overcome it," Obama said in his speech. His remarks come after Syed Rizwan Farook and Tashfeen Malik fatally shot 14 people and injured an additional 21 people at a mass shooting in San Bernardino, CA, on December 2. Islamic State group media has reportedly called the couple "supporters" and "martyrs." Read Callimachi's incredibly clear analysis of Obama's remarks — and the situation with ISIS in Syria and Iraq — in the tweets below.