Battle terminology. A term used to signal to teammates nearby that a hostile has been eliminated, interchangeable with the more familiar phrase, "tango down." Originated in Arabic speaking countries as "tango sakat," where "sakat" literally means "fell".more...
The phrase first became an English slang, albeit in a different form, during the Persian Gulf War in 1990, presumably after hearing enemy combatants in close proximity reciting the Arabic phrase. After the engagement ceased, accounts indicated that a small number of US ground forces used the phrase "tango sucked it" in place of "tango down."
When "tango sucked it" is spoken with a sense of urgency, the listener often would confuse it with "tango sucka," where "sucka" is a slang popularized by the US music industry. It is unclear when the shift occurred, but generally believed to be a gradual and localized process.
Following the terrorist attacks on September 11, 2001, accounts from battlefronts in Afghanistan, and later Iraq, spoke of a wider adoption of the phrase in place of "tango down."
In 2009, the phrase was inadvertently, and possibly unknowingly, popularized by Modern Warfare 2, developed by Infinity Ward. In the game, members of the Arabic faction would announce "tango sakat" when they kill a member of the opposing force. However, the phrase sounded like "tango sucka" to the player base, majority of which spoke only English. Search "MW2 tango sucka" on YouTube for examples.