WASHINGTON (AP) — President Joe Biden is saluting the nation’s military veterans as “the spine of America” as he marks his first Veterans Day as president in a wreath-laying ceremony at Arlington National Cemetery. Biden said “there’s nothing low risk or low cost about war for the women and men who fight it.” Earlier Thursday, his administration announced a federal effort to better understand, identify and treat medical conditions suffered by troops deployed to toxic environments. Biden’s son, Beau, died of brain cancer after his return from serving in Iraq. The president’s toxic-air effort announced Thursday centers on lung problems suffered by troops who breathe in toxins.