Barack Obama
US President Barack Obama taken to court by an army officerSaul Loeb/ AFP

A 28-year-old army officer stationed in Kuwait has dragged US President Barack Obama to court, questioning the legality of his decision to increase troops in Iraq and Syria to counter Islamic State (Isis).

Capt. Nathan Michael Smith, an intelligence officer, claimed in the lawsuit that Obama's decision of waging a war against IS (Daesh) lacks proper authorisation from the Congress, while the president has claimed that he does not need any new legal authority from the Congress to issue such orders to the military, The New York Times reported.

The president has maintained that powers given to him by the Congress after the 11 September 2001 terror attacks enable him to wage a war against IS operatives but critics believe he is stretching the authorisation too far, given the fact that IS is at odds with the leadership of al Qaeda, which perpetrated the 2001 attacks.

Further, IS did not exist in 2001 and does not operate out of Afghanistan like the Osama Bin Laden-led al Qaeda. But the Obama administration argued that IS used to be an al Qaeda affiliate in Iraq during the Iraq war and Laden's death does not mean the country stops its fight against the affiliates.

The lawsuit comes after a third American service member lost his life fighting IS militants in the recent past. Although in complete support of fighting the militants, the army officer said taking a decision without the Congress's authorisation was not in compliance with the constitutional process.

"To honor my oath, I am asking the court to tell the president that he must get proper authority from Congress, under the War Powers Resolution, to wage the war against ISIS in Iraq and Syria," the army officer reportedly said in the lawsuit. He is being represented by lawyer David Remes, who has been the lawyer for many Guantánamo detainees in habeas corpus lawsuits, and Bruce Ackerman, a Yale Law School professor.