Is it political strategy, donor pressure or perhaps hubris? Nikki Haley is vowing "the fight goes on" against Donald Trump, positioning herself as a viable option in case the scandal-plagued Republican frontrunner's campaign implodes. Haley has gone 0 for 4 in early contests for the GOP presidential nomination, including an embarrassing 20-point defeat Saturday in her home state of South Carolina where she served as governor. With her path to victory shrinking, her decision not to bow out is raising questions about her endgame in a party ruled by Trump.

WHY HALEY IS PLANNING TO FIGHT ON INTO SUPER TUESDAY

US and British forces carried out a fresh wave of strikes against Houthi targets in Yemen, following weeks of unrelenting attacks on Red Sea shipping by the Iran-backed rebels. The strikes "targeted 18 Houthi targets across eight locations in Yemen" including weapons storage facilities, attack drones, air defense systems, radars, and a helicopter. It was co-signed by Australia, Bahrain, Denmark, Canada, Netherlands and New Zealand, which gave "support" to the new round of strikes.

HOW THE HOUTHIS REMAIN A THREAT TO RED SEA COMMERCE

Ukrainian President Volodymyr Zelensky said on Sunday that 31,000 Ukrainian soldiers had been killed since Russia's full-scale invasion two years ago, giving the first official figure for more than a year. Zelensky said his country's victory "depends" on Western support and that he was "sure" the US would approve a critical package of military aid. The second anniversary of Russia's invasion came as Ukraine has been hurt by a shortage of ammunition and Congress' blocking of US aid.

HEAR ZELENSKY'S PLEA FOR MORE HELP FROM THE WEST

On this date in 1616, who was told to abandon his heliocentric belief?

Friday's answer: Andrew Johnson became the first U.S. president to be impeached on Feb. 23, 1868. He was succeeded by U.S. Grant.