A fourth member of an alleged Virginia jihad network pleaded guilty on Monday to preparing to fight for Muslim causes abroad and told a federal judge that he and his co-conspirators may have taken up arms against the US if they had not been arrested.Muhammed Aatique, 30, of Norristown, Pa., said he used paintball games to train for combat and he fired weapons in Pakistan at a Lashkar-e-Toiba camp. He is one of 11 men charged in the conspiracy. As he pleaded guilty, Aatique was asked by US District Judge Leonie Brinkema in Alexandria, Va.: ‘‘Did you understand that one of the countries against whom you might ultimately have to pick up arms could be the US?’’ ‘‘Yes,’’ Aatique replied. ‘‘The US could have been an opponent if the conspiracy had gone ahead.’’Federal officials have said repeatedly that the 11 men were a threat to the US, even though they are charged only with weapons counts and with preparing to wage jihadi combat overseas for Lashkar-e-Toiba. The men were charged with violating the Neutrality Act, which bars US citizens and residents from attacking countries with which US is at peace — in this case, India.Three defendants — Yong Ki Kwon, 27, of Fairfax County, Khwaja Mahmood Hasan, 27, also of Fairfax, and Donald T. Surratt, 30, of Suitland, — pleaded guilty to conspiracy and gun charges.Prosecutors indicated at Monday’s hearing that they plan to present additional charges to a federal grand jury this week. They did not say who would face the charges, but attorneys for Ali Al-Timimi of Fairfax County, a US citizen and Islamic preacher, have said he expects to be indicted. Prosecutors did not name Timimi, but the grand jury alleged that in mid-September 2001, a conspirator later identified as Timimi told seven of the defendants ‘‘the time had come for them to . join the mujahideen engaged in violent jihad in Kashmir, Chechnya, Afghanistan or Indonesia.’’He added that ‘‘American troops were legitimate targets of the jihad,’’ the indictment alleged. Aatique pleaded guilty to aiding and abetting other defendants in preparing to fight India and to using and discharging a firearm during a crime of violence. He faces up to life in prison when he is sentenced on December 12, although his sentence under federal guidelines is expected to be less than 20 years. — LAT-WP