If you have purchased Red Orchestra 2 near launch, it has now been split into two separate applications in your Steam Library - Rising Storm/Red Orchestra Multiplayer and Red Orchestra 2 Single Player.
The multiplayer part of the game now includes Rising Storm (pacific theater) content which you can access and play for free (as a rifleman only) or purchase for full access to.
The Steam
store page for Red Orchestra 2 no longer includes the single player and comes with both sets of multiplayer content (This switch happened in September 2014. The store page the game takes you to is the updated one, but may not be the one you purchased, which can be confusing). But you need to purchase the
Rising Storm package from steam for full access.
If you purchased the Rising Storm package previously or recently purchased the Red Orchestra 2 package, there is no way to get the Red Orchestra 2 Single Player. It is not available for sale.
This is a breakdown of what shows up in your Steam Library and what you own based on when you purchased it.
Red Orchestra 2 - From original launch to September 2014 -
http://store.steampowered.com/app/35450/Red Orchestra 2 Single Player
Rising Storm/Red Orchestra 2 Multiplayer - Rising Storm multiplayer content is not owned.
Red Orchestra 2 - From September 2014 til Now -
http://store.steampowered.com/app/35450/Rising Storm/Red Orchestra 2 Multiplayer - Full content
Rising Storm - From Launch til Now -
http://store.steampowered.com/app/234510/Rising Storm/Red Orchestra 2 Multiplayer - Full content
For some users who purchased Rising Storm or Red Orchestra 2 after September 2014 they see the message that they do not have Rising Storm. In this case please check the DLC tab for the game in Steam and make sure the DLC checkbox is selected for the Rising Storm content.