How many countries has the US bombed since 2001 and how much has it cost?

Since September 11, 2001, the US has engaged in three full-scale wars and bombed at least 10 countries, including Afghanistan, Iraq, Yemen, Pakistan, Somalia, Libya, Syria, Venezuela, Nigeria and Iran. The US spent an estimated $5.8 trillion on these conflicts, with total costs expected to reach $8 trillion including future veterans' care.