The first wave of National Guard troops assigned to the U.S.-Mexico border in San Diego have arrived as part of President Barack Obama's border security plan.Sources told 10News several National Guard members arrived Thursday, and Border Patrol officials said 217 National Guard troops from across the state will arrive within a week.10News learned an additional 90 troops will arrive Friday, and both the National Guard and Border Patrol will go through a two-week training period.National Guard troops will be armed, but they will not be involved in direct law enforcement."We are the additional eyes and ears for [the] Border Patrol," said Kimberly Holman, spokeswoman for the California National Guard.Unlike the previous deployment of troops, 10News learned nearly all the troops will act as lookouts this time. Some of the troops will be operating in observation posts, with others operating infrared scopes.Former U.S. Attorney Pete Nunez said, "This is tokenism at its worst. When the heat's on, presidents react."Nunez called it presidential posturing. Even with the border security bill that could be signed Friday -- which would bring 1,500 more troops along the entire border -- Nunez said more troops are needed. He pointed to numbers that showed an increase in apprehensions during the National Guard's last deployment.When the National Guard left, the storyline changed. The following year, apprehensions went down about 25 percent.The Border Patrol said not as many National Guard troops are needed this time, in part, because of recent growth in its own ranks and advances in technology.