US attitude is a wide view which cannot be answered. US includes the common folk - majority- and the new order in power which simply wants to eliminate Israel from the face of the earth. Your question makes it look as if US was in one mind on this, but nothing can be further from the truth. Obama announced that; "US is no longer a Christian Nation..." to the surprise of about 80% of Americans. Now it is up to those Christians, and those who still believe in freedom -Christian or not- who have sat in silence since this (satanic) power took over, to speak out. But as you can see, they were told to 'pray quitely' and they simply obey, why? "well, because we don't want to offend anyone." But letting a president in office who actually opposes Biblical teachings and ridicule its meaning as being 'foolish' and 'destructive' to the fabric of this nation, (and yet this was the very thing that held the Nation together for two hundred years, Jew and Arab living door to door to each other) is just sad. As I see it, Israel is facing the same fate, and once Satan achieved this, being a Jew in Israel will be 'politically incorect', as funny as that sounds.

So, 'how much will the US's attitude toward Israel change?', it depends which part of 'US' you are talking about. Those that are 'with us' (as with Bush) or those that are 'against us'? And the answer is: Nothing has changed, the attitude of the people has remained the same, only the power to controll has changed, and the one who has the power their attitude has not changed for over seventy years. "The Jew, the blacks and all the Jew-lovers must die! - and we know who you are..., we are watching you, ..."

But there is another who is watching us, all of us with an x-ray vision far better then theirs. IT IS; "... the word of God, (which) is living and powerful, and sharper than any two-edged sword, piercing even to the division of soul and spirit, and of joints and marrow, and is a discerner of the thoughts and intents of the heart. 13 And there is no creature hidden from His sight, but all things are naked and open to the eyes of Him to whom we must give account.

Israel, Israel, the Giant has once again stood upon the mountain, and seem to have scared you and is calling out blesphamies against your God (my God) and is saying; "I defy the armies of Israel this day; give me a man, that we may fight together." 11 When Saul and all Israel heard these words of the Philistine, they were dismayed and greatly afraid.1 Sam 17:10-11
NKJV

He is just like Goliath, except he has one eye like a cyclops, and calls it an 'all-seeing eye', so I ask you Israel, do you know who is; "this Philistine and takes away the reproach from Israel? For who is this uncircumcised Philistine, that he should defy the armies of the living God?" I tell you Israel, I have stood up against evil sinnce I was old enough to talk: "and this uncircumcised Philistine will be like one of them, seeing he has defied the armies of the living God." 1 Sam 17:36 and this I would do without even raising a sword, but like David, using the 'rock' that your people have rejected for 2,000 years, 7 ... "The stone which the builders rejected
Has become the chief cornerstone,"  

8 and "A stone of stumbling
And a rock of offense."
NKJV, 1 Peter 2:7-8

'But...' you might say, 'you are a gentile, how can you compare yourself to David?

I tell you it is by Him that proclaimed that I am:

"9 ... a chosen generation, a royal priesthood, a holy nation, His own special people, that you may proclaim the praises of Him who called you out of darkness into His marvelous light; 10 who once were not a people but are now the people of God, who had not obtained mercy but now have obtained mercy.
NKJV  1 Peter 2:9-10

So as was with David, he didn't actually kill the Giant, but the stone (the Rock) did. You have failed to closely examine the 'rock' that David flung from his sling, for you would have seen that it was 'Christ', the 'Messiah', a pre-view or 'fore-taste' of things to come. This is why I have: "11 Put on the whole armor of God, that you (I) may be able to stand against the wiles of the devil. 12 For we do not wrestle against flesh and blood, but against principalities, against powers, against the rulers of the darkness of this age, against spiritual hosts of wickedness in the heavenly places."
NKJV Eph 6:11-12

Listen to me now,Ezek 37:3
3 And He said to me, "Son of man, can these bones live?"
... 7 So I prophesied as I was commanded; and as I prophesied, there was a noise, and suddenly a rattling; and the bones came together, bone to bone. 8 Indeed, as I looked, the sinews and the flesh came upon them, and the skin covered them over; but there was no breath in them.

So the Gentile Christians came from the four winds

Ezek 37:9
9 Also He said to me, "Prophesy to the breath, prophesy, son of man, and say to the breath, 'Thus says the Lord GOD:"Come from the four winds, O breath, and breathe on these slain, that they may live."'"
NKJV

Now comes the main part; "My Spirit in you, and you shall live!"

Ezek 37:14
14 I will put My Spirit in you, and you shall live, and I will place you in your own land. Then you shall know that I, the LORD, have spoken it and performed it," says the LORD.'"
NKJV

Untill you recieve the Holy Spirit, you are not truly alive, even though you live. When you accept Christ as your King, it is THEN that you shall truly live! I would love to help you, that is if it's our Lords will.

shalom oh blessed of the Father, fear not and listen: "26 "Men and brethren, sons of the family of Abraham, and those among you who fear God, to you the word of this salvation has been sent. 27 For those who dwell in Jerusalem, and their rulers, because they did not know Him, nor even the voices of the Prophets which are read every Sabbath, have fulfilled them in condemning Him. Acts 13:26-27  NKJV

Rom 11:15-17
15 For if their being cast away is the reconciling of the world, what will their acceptance be but life from the dead?