The Sino-American presidential summit at Sunnylands is now history but many of the real results emanating from it may not be known for months or years. By necessity we are not privy to discussions of certain of the most critical of our bilateral issues, such as cyber-spying, but like a newly started garden many seeds were planted. If carefully nurtured, we can look forward to bright skies and a rich harvest. If not, the winds of change could blow both sides in a direction from which neither side will benefit.

Harvard Professor Joseph Nye said that the summit was the most important meeting between the two countries since those between Chairman Mao and President Nixon in 1972 that led to the establishment of bilateral diplomatic relations. I believe that in some ways the Xi-Obama meeting is even more important as we now live in a far different and infinitely more complex world from that of the Cold War.

Back then life was simpler. The US and USSR were the major superpowers. Both had advanced nuclear weapons that with the push of a button could take the world back to the Stone Age. China and the Soviets had a major schism. Both China and the US had good reasons to bury the hatchet. The enemy of my enemy is my friend.

Back then with Mutually Assured Destruction, the use of nuclear weapons could lead to Armageddon and almost did. Today with cyber-warfare and drone miniaturization, choices and consequences are greater and vastly more complicated.

Today we live in a world becoming more and more multi-polar. Sure, the US is the super power and China is rising fast to meet it, but there will be important regional actors such as Russia, and middle powers such as Indonesia who will demand to be heard.

While there were few so-called "deliverables", there was a meeting of the mind on phase-out of environmentally destructive hydrofluorocarbons. And there was a consensus view on the DPRK's nuclear weapons program.

For me, the most important outcome was that our two militaries would begin to try to forge closer cooperation, increase the intensity and frequency of their dialogue, and better understand the positions, fears and hopes of the other side. A lack of knowledge can only breed suspicion and hostility. Closer sharing of views, even where both sides agree to disagree is a strong positive.

There seems to be an especially high level of mistrust and suspicion about the military intentions of both sides. Conducting joint exercises, having more bilateral military discussions, and sharing hopes and fears can go a long way to defusing simmering tensions.