I think you've missed a word; do you mean: explain why do presidents think that military is important.
Military is important for security, and without the military a country can't defend itself: see the attack on Pearl Harbor.
With a strong army the president has more power and cannot be threatened by other countries.
Interactions help these living things survive in the following ways: A
bee pollinates a dandelion, which helps dandelions to survive because it
means this pollen is passed to other plants, allowing them to spread
further. Pollination helps bees because it allows them to make honey
which they need to survive. Hawks then need to eat insects such as bees
to survive, so this pollination is also in their best interest as it
aids a healthy bee population.
