The U.N., no. It's an organization mostly of tyrants and dictators.
Ignoring this part, I think you are falling into moral equivalence. To take an extreme example: did we have the right to get control over Hitler and disrespect their sovereignty? Of course, because they were a threat to our freedom.
Do Israel's enemies threaten our freedom? I think so. Does our support for allies against them cause them to threaten our freedom? I don't see the logical argument for that. They wish to triumph over all free nations and bring them under the rule of Islam. To them, we are their eternal enemies until we are subdued.
We have the right to intervene for our own protection, that is not questionable, IMHO. We can debate where that is justified, how much, at what cost, when, etc. But not the basic concept. All governments, all nations are not morally equivalent. There are very bad and dangerous ones out there. Always will be.
Speaking of that, here's a quote...
"Observe good faith and justice toward all nations. Cultivate peace and harmony with all....The nation which indulges toward another an habitual hatred or an habitual fondness is in some degree a slave. It is a slave to its animosity or to its affection, either of which is sufficient to lead it astray from its duty and its interest."
- George Washington, 1797