I think that number is a little sensationalist. What's the net present value of the obligations? My simplified calculation makes these assumptions:<p><pre><code> 1. Discount rate of 0.04.
2. Uniform payments of the entire $2 trillion over the next twenty years.
</code></pre>
Under those assumptions the present value is only about $1.4 trillion over twenty years, or about $70 billion per year. A substantial sum, to be sure, but not compared to a number of other things we do. A higher discount rate around 6% decreases the yearly cost about 20%.