Here's a little refresher course:
The dollar: China goes to great lengths to compete for our business---making us wealthier in the process (we enjoy more of life's amenities as the world competes on price for our business)---because they love U.S. dollars. They love U.S. dollars because we apparently yet produce goods (like hogs) and services they deem valuable. The Smithfield Foods acquisition proves it. Thank goodness we have more than just federal debt to offer the world.
Jobs: Trust me, Chinese management and workers are not about to descend upon tiny Smithfield, Virginia. Shaunghui bought Smithfield Foods to exploit, and export (or import), its business model (along with its hogs). But we're not talking merely the preservation of Smithfield jobs, we're talking $4.7 billion U.S. dollars (a few of them you sent to China to buy the monitor, tablet, or cell phone you're staring at right now*) flowing back to the U.S. You think Smithfield's largest shareholders might be looking to grow other successful enterprises with their proceeds --- creating jobs in the process? Yyyyep!
*So the next time you cringe before buying an item made in China, remember all those U.S. jobs you helped create when Shaunghui bought Smithfield Foods.
Worried about national security? This one's the easiest: Nobody ever shoots their customer (or supplier). Or, as an intuitive individual (most often ascribed to Frederic Bastiat) once said:
"If goods don't cross borders, soldiers will."