How did world war 1 blur the line between civilian and military life?
It blurred the line because American civilians [not to mention the boys off at war] had to invest their lives in making money, bullets, guns, and all the other supplies necessary to fuel a war.
You can easily add blur using depth of Field in Guided Edit or from Filter > Blur > Gaussian Blur, Motion Blur... When using blur filter from Filter menu first duplicate layer with image, apply blur filter then create layer mask and use Gradient Tool on layer mask (set foreground background colors to black/white) to restrict blur only to some areas of the image.
You can use the Blur tool from the Tools palette, adjust the brush size to increase and decrease the size of the blur, and adjust the amount of the blurriness with the Strength value, then click and drag the tool along the edges of the picture to apply it. OR If you want a more precise and uniform blur, you can use the "Rectangular Marquee" tool to select an area inside the image that you…
To blur pictures in Photoshop don't worry.... Open or select your pictures layer and go to menus: Filter --> Blur. Now you will see 11 different - 2 types of blur. I do not know that which type of blur you want. So use all of them one by one. Some of them have their own properties, set the properties as per your requirement. Hope this help Saqib